dt-bindings: i2c: i2c-mt65xx: add MediaTek MT7981 SoC

Add compatible string for the I2C controllers found in the MediaTek
MT7981 SoC.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Documentation/devicetree/bindings/i2c/i2c-mt65xx.yaml

@@ -23,6 +23,7 @@ properties:
       - const: mediatek,mt6577-i2c
       - const: mediatek,mt6589-i2c
       - const: mediatek,mt7622-i2c
+      - const: mediatek,mt7981-i2c
       - const: mediatek,mt7986-i2c
       - const: mediatek,mt8168-i2c
       - const: mediatek,mt8173-i2c