dt-bindings: display: mediatek: Add binding for MT8195 HDMI-TX v2

dt-bindings: display: mediatek: Add binding for MT8195 HDMI-TX v2

Add a binding for the HDMI TX v2 Encoder found in MediaTek MT8195
and MT8188 SoCs.

This fully supports the HDMI Specification 2.0b, hence it provides
support for 3D-HDMI, Polarity inversion, up to 16 bits Deep Color,
color spaces including RGB444, YCBCR420/422/444 (ITU601/ITU709) and
xvYCC, with output resolutions up to 3840x2160p@60Hz.

Moreover, it also supports HDCP 1.4 and 2.3, Variable Refresh Rate
(VRR) and Consumer Electronics Control (CEC).

This IP also includes support for HDMI Audio, including IEC60958
and IEC61937 SPDIF, 8-channel PCM, DSD, and other lossless audio
according to HDMI 2.0.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20250415104321.51149-3-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>