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

By attach a driver private struct to each open drm fd.

Because we steal the owner_list from drm_sman until things settle,
use list_move instead of list_add.

This requires to export a drm_sman function temporarily before
drm_sman will die for real completely.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/include/drm/sis_drm.h b/include/drm/sis_drm.h
index 30f7b38..035b804 100644
--- a/include/drm/sis_drm.h
+++ b/include/drm/sis_drm.h
@@ -64,4 +64,8 @@
 	unsigned int offset, size;
 } drm_sis_fb_t;
 
+struct sis_file_private {
+	struct list_head obj_list;
+};
+
 #endif				/* __SIS_DRM_H__ */