drm: Fix compilation warning caused by static inline forward declaration

The drm_crtc_mask() function used in <drm/drm_encoder.h> is a static
inline defined in <drm/drm_crtc.h>. If the first header is included in a
compilation unit without the second one, the following compilation
warning will be issued.

In file included from <linux>/drivers/gpu/drm/drm_bridge.c:29:0:
<linux>/include/drm/drm_encoder.h:192:95: warning: ‘drm_crtc_mask’ used but never defined
static inline uint32_t drm_crtc_mask(const struct drm_crtc *crtc);

Fix this by including the header defining the function instead of using
a forward declaration.

Signed-off-by: Laurent Pinchart <[e-mail]>
Reviewed-by: Daniel Vetter <[e-mail]>
Signed-off-by: Archit Taneja <[e-mail]>
Link: http://patchwork.freedesktop.org/patch/msgid/[e-mail]

include/drm/drm_encoder.h

···
 
 #include <linux/list.h>
 #include <linux/ctype.h>
+#include <drm/drm_crtc.h>
 #include <drm/drm_mode.h>
 #include <drm/drm_mode_object.h>
 
···
 {
 	return encoder->index;
 }
-
-/* FIXME: We have an include file mess still, drm_crtc.h needs untangling. */
-static inline uint32_t drm_crtc_mask(const struct drm_crtc *crtc);
 
 /**
  * drm_encoder_crtc_ok - can a given crtc drive a given encoder?