dt-bindings: mediatek: mmsys: add mt8167 binding

Add binding documentation for MT8167 SoC.
Signed-off-by: Fabien Parent <fparent@baylibre.com>
Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210405200354.2194930-1-fparent@baylibre.comSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>

Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.txt

@@ -13,6 +13,7 @@ Required Properties:
 	- "mediatek,mt6779-mmsys", "syscon"
 	- "mediatek,mt6797-mmsys", "syscon"
 	- "mediatek,mt7623-mmsys", "mediatek,mt2701-mmsys", "syscon"
+	- "mediatek,mt8167-mmsys", "syscon"
 	- "mediatek,mt8173-mmsys", "syscon"
 	- "mediatek,mt8183-mmsys", "syscon"
 - #clock-cells: Must be 1