dt-bindings: i2c: update bindings for MT8168 SoC

Add a DT binding documentation for the MT8168 soc.

Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Author: Kewei Xu

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

@@ -12,6 +12,7 @@ Required properties:
       "mediatek,mt7622-i2c": for MediaTek MT7622
       "mediatek,mt7623-i2c", "mediatek,mt6577-i2c": for MediaTek MT7623
       "mediatek,mt7629-i2c", "mediatek,mt2712-i2c": for MediaTek MT7629
+      "mediatek,mt8168-i2c": for MediaTek MT8168
       "mediatek,mt8173-i2c": for MediaTek MT8173
       "mediatek,mt8183-i2c": for MediaTek MT8183
       "mediatek,mt8186-i2c": for MediaTek MT8186