dt-bindings: i2c: Document I2C controller binding for MT6797 SoC

I2C controller driver for MT6577 SoC is reused for MT6797 SoC. Hence,
document that in DT binding.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Wolfram Sang <wsa@kernel.org>
Link: https://lore.kernel.org/r/20200222162444.11590-2-manivannan.sadhasivam@linaro.orgSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>

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

@@ -8,6 +8,7 @@ Required properties:
       "mediatek,mt2712-i2c": for MediaTek MT2712
       "mediatek,mt6577-i2c": for MediaTek MT6577
       "mediatek,mt6589-i2c": for MediaTek MT6589
+      "mediatek,mt6797-i2c", "mediatek,mt6577-i2c": for MediaTek MT6797
       "mediatek,mt7622-i2c": for MediaTek MT7622
       "mediatek,mt7623-i2c", "mediatek,mt6577-i2c": for MediaTek MT7623
       "mediatek,mt7629-i2c", "mediatek,mt2712-i2c": for MediaTek MT7629