drm/mediatek: call drm_atomic_helper_shutdown() when unbinding driver

shutdown all CRTC when unbinding drm driver.

Fixes: 119f5173 ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.")
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: CK Hu <ck.hu@mediatek.com>

drivers/gpu/drm/mediatek/mtk_drm_drv.c

@@ -311,6 +311,7 @@ static int mtk_drm_kms_init(struct drm_device *drm)
 static void mtk_drm_kms_deinit(struct drm_device *drm)
 {
 	drm_kms_helper_poll_fini(drm);
+	drm_atomic_helper_shutdown(drm);
 
 	component_unbind_all(drm->dev, drm);
 	drm_mode_config_cleanup(drm);