drm: Extract drm_bridge.h

We don't want to burry the bridge structures kerneldoc in drm_crtc.h.

Cc: Archit Taneja <archit.taneja@gmail.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160831160913.12991-3-daniel.vetter@ffwll.ch
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
index 986ed6f..9934d91 100644
--- a/include/drm/drm_modes.h
+++ b/include/drm/drm_modes.h
@@ -27,9 +27,13 @@
 #ifndef __DRM_MODES_H__
 #define __DRM_MODES_H__
 
+#include <linux/hdmi.h>
+
 #include <drm/drm_mode_object.h>
 #include <drm/drm_connector.h>
 
+struct videomode;
+
 /*
  * Note on terminology:  here, for brevity and convenience, we refer to connector
  * control chips as 'CRTCs'.  They can control any type of connector, VGA, LVDS,