drm/displayid: move drm_displayid.h to drm_displayd_internal.h

There are no exported symbols for displayid, and it's all internal
interfaces. Move the header to drivers/gpu/drm/drm_displayd_internal.h.

Reviewed-by: Thomas Zimmermann <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/220[e-mail]
Signed-off-by: Jani Nikula <[e-mail]>

drivers/gpu/drm/drm_displayid.c

···
  * Copyright © 2021 Intel Corporation
  */
 
-#include <drm/drm_displayid.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_print.h>
+
+#include "drm_displayid_internal.h"
 
 static const struct displayid_header *
 displayid_get_header(const u8 *displayid, int length, int index)

drivers/gpu/drm/drm_edid.c

···
 #include <linux/slab.h>
 #include <linux/vga_switcheroo.h>
 
-#include <drm/drm_displayid.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_eld.h>
···
 #include <drm/drm_print.h>
 
 #include "drm_crtc_internal.h"
+#include "drm_displayid_internal.h"
 #include "drm_internal.h"
 
 static int oui(u8 first, u8 second, u8 third)

include/drm/drm_displayid.h drivers/gpu/drm/drm_displayid_internal.h

···
  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  * OTHER DEALINGS IN THE SOFTWARE.
  */
-#ifndef DRM_DISPLAYID_H
-#define DRM_DISPLAYID_H
+
+#ifndef __DRM_DISPLAYID_INTERNAL_H__
+#define __DRM_DISPLAYID_INTERNAL_H__
 
 #include <linux/types.h>
 #include <linux/bits.h>