drm: Remove unused DRM_MODE_OBJECT_BRIDGE

With bridges now moving to a separate registry they are no longer DRM
objects, hence this define is no longer needed.
Signed-off-by: Thierry Reding <treding@nvidia.com>

include/drm/drm_crtc.h

@@ -53,7 +53,6 @@ struct fence;
 #define DRM_MODE_OBJECT_FB 0xfbfbfbfb
 #define DRM_MODE_OBJECT_BLOB 0xbbbbbbbb
 #define DRM_MODE_OBJECT_PLANE 0xeeeeeeee
-#define DRM_MODE_OBJECT_BRIDGE 0xbdbdbdbd
 #define DRM_MODE_OBJECT_ANY 0
 
 struct drm_mode_object {