drm/rockchip: select DEBUG_FS for ROCKCHIP_DRM_DEBUG

ROCKCHIP_DRM_DEBUG will call API from debugfs, need to select DEBUG_FS.

Change-Id: I06a7c7c2ce9179796e551727fdd2e08313bfe6ff
Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>

Author: jayxurockchip

drivers/gpu/drm/rockchip/Kconfig

@@ -18,7 +18,7 @@ config DRM_ROCKCHIP
 
 config ROCKCHIP_DRM_DEBUG
 	tristate "Rockchip DRM debug"
-	depends on DRM_ROCKCHIP
+	depends on DRM_ROCKCHIP && DEBUG_FS
 	help
 	  This option add a debug nod to dump buf from application.
 	  dump path: /data/vop_buf