drm: bridge: Constify mode arguments to bridge .mode_set() operation

The mode and ajusted_mode passed to the bridge .mode_set() operation
should never be modified by the bridge (and are not in any of the
existing bridge drivers). Make them const to make this clear.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/sti/sti_hda.c

@@ -508,8 +508,8 @@ static void sti_hda_pre_enable(struct drm_bridge *bridge)
 }
 
 static void sti_hda_set_mode(struct drm_bridge *bridge,
-		struct drm_display_mode *mode,
-		struct drm_display_mode *adjusted_mode)
+			     const struct drm_display_mode *mode,
+			     const struct drm_display_mode *adjusted_mode)
 {
 	struct sti_hda *hda = bridge->driver_private;
 	u32 mode_idx;