MAINTAINERS: Add linux-mediatek ML for drm Mediatek drivers

Add the linux-mediatek mailing list to drm Mediatek drivers
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

MAINTAINERS

@@ -5963,6 +5963,7 @@ DRM DRIVERS FOR MEDIATEK
 M:	Chun-Kuang Hu <chunkuang.hu@kernel.org>
 M:	Philipp Zabel <p.zabel@pengutronix.de>
 L:	dri-devel@lists.freedesktop.org
+L:	linux-mediatek@lists.infradead.org (moderated for non-subscribers)
 S:	Supported
 F:	Documentation/devicetree/bindings/display/mediatek/
 F:	drivers/gpu/drm/mediatek/