drm/bridge/analogix/anx78xx: Add missing drm_dp_aux_unregister() call

Surprisingly, this bridge actually registers it's AUX adapter at the
correct time already. Nice job! However, it does forget to actually
unregister the AUX adapter, so let's add a bridge function to handle that.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219215326.2227596-8-lyude@redhat.com

drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c

@@ -942,6 +942,11 @@ static int anx78xx_bridge_attach(struct drm_bridge *bridge,
 	return 0;
 }
 
+static void anx78xx_bridge_detach(struct drm_bridge *bridge)
+{
+	drm_dp_aux_unregister(&bridge_to_anx78xx(bridge)->aux);
+}
+
 static enum drm_mode_status
 anx78xx_bridge_mode_valid(struct drm_bridge *bridge,
 			  const struct drm_display_info *info,
@@ -1013,6 +1018,7 @@ static void anx78xx_bridge_enable(struct drm_bridge *bridge)
 
 static const struct drm_bridge_funcs anx78xx_bridge_funcs = {
 	.attach = anx78xx_bridge_attach,
+	.detach = anx78xx_bridge_detach,
 	.mode_valid = anx78xx_bridge_mode_valid,
 	.disable = anx78xx_bridge_disable,
 	.mode_set = anx78xx_bridge_mode_set,