gpu: drm: bridge: sii9234: remove unused bridge_to_sii9234 function

clang with W=1 reports
drivers/gpu/drm/bridge/sii9234.c:870:31: error:
  unused function 'bridge_to_sii9234' [-Werror,-Wunused-function]
static inline struct sii9234 *bridge_to_sii9234(struct drm_bridge *bridge)
                              ^
This static function is not used, so remove it.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230318002321.1675181-1-trix@redhat.com

drivers/gpu/drm/bridge/sii9234.c

@@ -867,11 +867,6 @@ static int sii9234_init_resources(struct sii9234 *ctx,
 	return 0;
 }
 
-static inline struct sii9234 *bridge_to_sii9234(struct drm_bridge *bridge)
-{
-	return container_of(bridge, struct sii9234, bridge);
-}
-
 static enum drm_mode_status sii9234_mode_valid(struct drm_bridge *bridge,
 					 const struct drm_display_info *info,
 					 const struct drm_display_mode *mode)