drm/rockchip: Use lockless gem BO free callback

No dev->struct_mutex anywhere to be seen.

Cc: Mark Yao <mark.yao@rock-chips.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464630800-30786-12-git-send-email-daniel.vetter@ffwll.ch

drivers/gpu/drm/rockchip/rockchip_drm_drv.c

@@ -316,7 +316,7 @@ static struct drm_driver rockchip_drm_driver = {
 	.enable_vblank		= rockchip_drm_crtc_enable_vblank,
 	.disable_vblank		= rockchip_drm_crtc_disable_vblank,
 	.gem_vm_ops		= &rockchip_drm_vm_ops,
-	.gem_free_object	= rockchip_gem_free_object,
+	.gem_free_object_unlocked = rockchip_gem_free_object,
 	.dumb_create		= rockchip_gem_dumb_create,
 	.dumb_map_offset	= rockchip_gem_dumb_map_offset,
 	.dumb_destroy		= drm_gem_dumb_destroy,