drm/via: track obj->drm_fd relations in the driver

Exactly like the previous patch for sis.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/include/drm/via_drm.h b/include/drm/via_drm.h
index fd11a5b..79b3b6e0 100644
--- a/include/drm/via_drm.h
+++ b/include/drm/via_drm.h
@@ -274,4 +274,8 @@
 	drm_via_blitsync_t sync;
 } drm_via_dmablit_t;
 
+struct via_file_private {
+	struct list_head obj_list;
+};
+
 #endif				/* _VIA_DRM_H_ */