dt-bindings: mediatek: add MT6797 power dt-bindings

This adds power dt-bindings for MT6797
Signed-off-by: Mars Cheng <mars.cheng@mediatek.com>
Signed-off-by: Kevin-CW Chen <kevin-cw.chen@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

Documentation/devicetree/bindings/soc/mediatek/scpsys.txt

@@ -9,11 +9,14 @@ domain control.
 
 The driver implements the Generic PM domain bindings described in
 power/power_domain.txt. It provides the power domains defined in
-include/dt-bindings/power/mt8173-power.h and mt2701-power.h.
+- include/dt-bindings/power/mt8173-power.h
+- include/dt-bindings/power/mt6797-power.h
+- include/dt-bindings/power/mt2701-power.h
 
 Required properties:
 - compatible: Should be one of:
 	- "mediatek,mt2701-scpsys"
+	- "mediatek,mt6797-scpsys"
 	- "mediatek,mt8173-scpsys"
 - #power-domain-cells: Must be 1
 - reg: Address range of the SCPSYS unit
@@ -22,6 +25,7 @@ Required properties:
                       These are clocks which hardware needs to be
                       enabled before enabling certain power domains.
 	Required clocks for MT2701: "mm", "mfg", "ethif"
+	Required clocks for MT6797: "mm", "mfg", "vdec"
 	Required clocks for MT8173: "mm", "mfg", "venc", "venc_lt"
 
 Optional properties: