drm/radeon/radeon_audio: Move 'dce6_*()'s prototypes to shared header

Fixes the following W=1 kernel build warning(s):

drivers/gpu/drm/radeon/dce6_afmt.c:32:5: warning: no previous prototype for ‘dce6_endpoint_rreg’ [-Wmissing-prototypes]
32 | u32 dce6_endpoint_rreg(struct radeon_device *rdev,
| ^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/radeon/dce6_afmt.c:46:6: warning: no previous prototype for ‘dce6_endpoint_wreg’ [-Wmissing-prototypes]
46 | void dce6_endpoint_wreg(struct radeon_device *rdev,
| ^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/radeon/dce6_afmt.c:110:6: warning: no previous prototype for ‘dce6_afmt_select_pin’ [-Wmissing-prototypes]
110 | void dce6_afmt_select_pin(struct drm_encoder *encoder)
| ^~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/radeon/dce6_afmt.c:123:6: warning: no previous prototype for ‘dce6_afmt_write_latency_fields’ [-Wmissing-prototypes]
123 | void dce6_afmt_write_latency_fields(struct drm_encoder *encoder,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/radeon/dce6_afmt.c:152:6: warning: no previous prototype for ‘dce6_afmt_hdmi_write_speaker_allocation’ [-Wmissing-prototypes]
152 | void dce6_afmt_hdmi_write_speaker_allocation(struct drm_encoder *encoder,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/radeon/dce6_afmt.c:177:6: warning: no previous prototype for ‘dce6_afmt_dp_write_speaker_allocation’ [-Wmissing-prototypes]
177 | void dce6_afmt_dp_write_speaker_allocation(struct drm_encoder *encoder,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/radeon/dce6_afmt.c:202:6: warning: no previous prototype for ‘dce6_afmt_write_sad_regs’ [-Wmissing-prototypes]
202 | void dce6_afmt_write_sad_regs(struct drm_encoder *encoder,
| ^~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/radeon/dce6_afmt.c:268:6: warning: no previous prototype for ‘dce6_hdmi_audio_set_dto’ [-Wmissing-prototypes]
268 | void dce6_hdmi_audio_set_dto(struct radeon_device *rdev,
| ^~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/radeon/dce6_afmt.c:287:6: warning: no previous prototype for ‘dce6_dp_audio_set_dto’ [-Wmissing-prototypes]
287 | void dce6_dp_audio_set_dto(struct radeo_device *rdev,
| ^~~~~~~~~~~~~~~~~~~~~

Cc: Alex Deucher <[e-mail]>
Cc: "Christian König" <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: Daniel Vetter <[e-mail]>
Cc: Slava Grigorev <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Lee Jones <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/radeon/dce6_afmt.c

···
  */
 #include <linux/hdmi.h>
 
+#include "dce6_afmt.h"
 #include "radeon.h"
 #include "radeon_audio.h"
 #include "sid.h"

drivers/gpu/drm/radeon/dce6_afmt.h

···
+/* dce6_afmt.h -- Private header for radeon driver -*- linux-c -*-
+ *
+ * Copyright 2013 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#ifndef __DCE6_AFMT_H__
+#define __DCE6_AFMT_H__
+
+struct cea_sad;
+struct drm_connector;
+struct drm_display_mode;
+struct drm_encoder;
+struct radeon_crtc;
+struct radeon_device;
+
+u32 dce6_endpoint_rreg(struct radeon_device *rdev, u32 offset, u32 reg);
+void dce6_endpoint_wreg(struct radeon_device *rdev, u32 offset, u32 reg, u32 v);
+void dce6_afmt_write_sad_regs(struct drm_encoder *encoder,
+			      struct cea_sad *sads, int sad_count);
+void dce6_afmt_hdmi_write_speaker_allocation(struct drm_encoder *encoder,
+					     u8 *sadb, int sad_count);
+void dce6_afmt_dp_write_speaker_allocation(struct drm_encoder *encoder,
+					   u8 *sadb, int sad_count);
+void dce6_afmt_write_latency_fields(struct drm_encoder *encoder,
+				    struct drm_connector *connector,
+				    struct drm_display_mode *mode);
+void dce6_afmt_select_pin(struct drm_encoder *encoder);
+void dce6_hdmi_audio_set_dto(struct radeon_device *rdev,
+			     struct radeon_crtc *crtc, unsigned int clock);
+void dce6_dp_audio_set_dto(struct radeon_device *rdev,
+			   struct radeon_crtc *crtc, unsigned int clock);
+
+#endif                         /* __DCE6_AFMT_H__ */

drivers/gpu/drm/radeon/radeon_audio.c

···
 #include <linux/gcd.h>
 
 #include <drm/drm_crtc.h>
+#include "dce6_afmt.h"
 #include "evergreen_hdmi.h"
 #include "radeon.h"
 #include "atom.h"
···
 		u8 enable_mask);
 void dce6_audio_enable(struct radeon_device *rdev, struct r600_audio_pin *pin,
 		u8 enable_mask);
-u32 dce6_endpoint_rreg(struct radeon_device *rdev, u32 offset, u32 reg);
-void dce6_endpoint_wreg(struct radeon_device *rdev,
-		u32 offset, u32 reg, u32 v);
-void dce6_afmt_write_sad_regs(struct drm_encoder *encoder,
-		struct cea_sad *sads, int sad_count);
-void dce6_afmt_hdmi_write_speaker_allocation(struct drm_encoder *encoder,
-		u8 *sadb, int sad_count);
-void dce6_afmt_dp_write_speaker_allocation(struct drm_encoder *encoder,
-		u8 *sadb, int sad_count);
-void dce6_afmt_write_latency_fields(struct drm_encoder *encoder,
-		struct drm_connector *connector, struct drm_display_mode *mode);
 struct r600_audio_pin* r600_audio_get_pin(struct radeon_device *rdev);
 struct r600_audio_pin* dce6_audio_get_pin(struct radeon_device *rdev);
-void dce6_afmt_select_pin(struct drm_encoder *encoder);
 void r600_hdmi_audio_set_dto(struct radeon_device *rdev,
-	struct radeon_crtc *crtc, unsigned int clock);
-void dce6_hdmi_audio_set_dto(struct radeon_device *rdev,
-	struct radeon_crtc *crtc, unsigned int clock);
-void dce6_dp_audio_set_dto(struct radeon_device *rdev,
 	struct radeon_crtc *crtc, unsigned int clock);
 void r600_set_avi_packet(struct radeon_device *rdev, u32 offset,
 	unsigned char *buffer, size_t size);