MAINTAINERS: update files for Amlogic DRM Driver

This patch adds the dw-hdmi bindings and RST kerneldoc to maintained files.
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491308131-22071-2-git-send-email-narmstrong@baylibre.com

MAINTAINERS

@@ -4257,6 +4257,8 @@ W:	http://linux-meson.com/
 S:	Supported
 F:	drivers/gpu/drm/meson/
 F:	Documentation/devicetree/bindings/display/amlogic,meson-vpu.txt
+F:	Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
+F:	Documentation/gpu/meson.rst
 T:	git git://anongit.freedesktop.org/drm/drm-misc
 
 DRM DRIVERS FOR EXYNOS