ARM: dts: exynos: Fix DTC unit name warnings in Exynos4x12

Fix following DTC warnings in Exynos4x12 boards:

Warning (unit_address_vs_reg): Node /camera/fimc-is@12000000/pmu has a reg or ranges property, but no unit name

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
diff --git a/arch/arm/boot/dts/exynos4x12.dtsi b/arch/arm/boot/dts/exynos4x12.dtsi
index 84a23f9..b7490ea0 100644
--- a/arch/arm/boot/dts/exynos4x12.dtsi
+++ b/arch/arm/boot/dts/exynos4x12.dtsi
@@ -179,7 +179,7 @@
 			ranges;
 			status = "disabled";
 
-			pmu {
+			pmu@10020000 {
 				reg = <0x10020000 0x3000>;
 			};