dt-bindings: phy: mediatek,hdmi-phy: Add support for MT8188 SoC

Add compatible string for the HDMI PHY IP on MT8188 SoC, that is
compatible with the one found on MT8195 SoC.

Signed-off-by: Louis-Alexis Eyraud <louisalexis.eyraud@collabora.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20251217-mtk-genio-evk-hdmi-support-v2-2-a994976bb39a@collabora.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

Author: laeyraud

Documentation/devicetree/bindings/phy/mediatek,hdmi-phy.yaml

@@ -26,6 +26,10 @@ properties:
           - enum:
               - mediatek,mt7623-hdmi-phy
           - const: mediatek,mt2701-hdmi-phy
+      - items:
+          - enum:
+              - mediatek,mt8188-hdmi-phy
+          - const: mediatek,mt8195-hdmi-phy
       - const: mediatek,mt2701-hdmi-phy
       - const: mediatek,mt8173-hdmi-phy
       - const: mediatek,mt8195-hdmi-phy