MAINTAINERS: Update the files list for the Renesas DRM drivers

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-renesas-soc@vger.kernel.org
Signed-off-by: NEmil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461279842-28695-9-git-send-email-emil.l.velikov@gmail.com

MAINTAINERS

@@ -3881,6 +3881,7 @@ S:	Supported
 F:	drivers/gpu/drm/rcar-du/
 F:	drivers/gpu/drm/shmobile/
 F:	include/linux/platform_data/shmob_drm.h
+F:	Documentation/devicetree/bindings/display/renesas,du.txt
 
 DRM DRIVERS FOR ROCKCHIP
 M:	Mark Yao <mark.yao@rock-chips.com>