ARM: dts: mediatek: rename scpsys nodes to power-controller

The nodes with name scpsys actually implement a power-controller.
Rename the nodes to match the bindings description.
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

arch/arm/boot/dts/mt2701.dtsi

@@ -148,7 +148,7 @@ syscfg_pctl_a: syscfg@10005000 {
 		reg = <0 0x10005000 0 0x1000>;
 	};
 
-	scpsys: scpsys@10006000 {
+	scpsys: power-controller@10006000 {
 		compatible = "mediatek,mt2701-scpsys", "syscon";
 		#power-domain-cells = <1>;
 		reg = <0 0x10006000 0 0x1000>;

arch/arm/boot/dts/mt7623.dtsi

@@ -268,7 +268,7 @@ syscfg_pctl_a: syscfg@10005000 {
 		reg = <0 0x10005000 0 0x1000>;
 	};
 
-	scpsys: scpsys@10006000 {
+	scpsys: power-controller@10006000 {
 		compatible = "mediatek,mt7623-scpsys",
 			     "mediatek,mt2701-scpsys",
 			     "syscon";

arch/arm/boot/dts/mt7629.dtsi

@@ -90,7 +90,7 @@ pericfg: syscon@10002000 {
 			#clock-cells = <1>;
 		};
 
-		scpsys: scpsys@10006000 {
+		scpsys: power-controller@10006000 {
 			compatible = "mediatek,mt7629-scpsys",
 				     "mediatek,mt7622-scpsys";
 			#power-domain-cells = <1>;