ARM: dts: exynos: Fix power domain node names for Exynos5250

Device nodes in device tree should use generic names, so rename
all existing domains to "power-domain".
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

arch/arm/boot/dts/exynos5250.dtsi

@@ -111,21 +111,21 @@ smp-sysram@2f000 {
 			};
 		};
 
-		pd_gsc: gsc-power-domain@10044000 {
+		pd_gsc: power-domain@10044000 {
 			compatible = "samsung,exynos4210-pd";
 			reg = <0x10044000 0x20>;
 			#power-domain-cells = <0>;
 			label = "GSC";
 		};
 
-		pd_mfc: mfc-power-domain@10044040 {
+		pd_mfc: power-domain@10044040 {
 			compatible = "samsung,exynos4210-pd";
 			reg = <0x10044040 0x20>;
 			#power-domain-cells = <0>;
 			label = "MFC";
 		};
 
-		pd_disp1: disp1-power-domain@100440A0 {
+		pd_disp1: power-domain@100440A0 {
 			compatible = "samsung,exynos4210-pd";
 			reg = <0x100440A0 0x20>;
 			#power-domain-cells = <0>;