dt-bindings: drm/mediatek: Add Mediatek HDMI dts binding

Add the device tree binding documentation for Mediatek HDMI,
HDMI PHY and HDMI DDC devices.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Rob Herring <robh@kernel.org>
1 file changed