drm/mediatek: Move gce event property to mutex device node

According mtk hardware design, stream_done0 and stream_done1 are
generated by mutex, so we move gce event property to mutex device mode.
Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
Signed-off-by: CK Hu <ck.hu@mediatek.com>

drivers/gpu/drm/mediatek/mtk_drm_crtc.c

@@ -836,7 +836,8 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 			drm_crtc_index(&mtk_crtc->base));
 		mtk_crtc->cmdq_client = NULL;
 	}
-	ret = of_property_read_u32_index(dev->of_node, "mediatek,gce-events",
+	ret = of_property_read_u32_index(priv->mutex_node,
+					 "mediatek,gce-events",
 					 drm_crtc_index(&mtk_crtc->base),
 					 &mtk_crtc->cmdq_event);
 	if (ret)