ARM: dts: Use labels for overriding nodes in exynos4212

Usage of labels instead of full paths reduces possible mistakes when
overriding nodes.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>

arch/arm/boot/dts/exynos4212.dtsi

@@ -41,12 +41,12 @@ cpu@A01 {
 			reg = <0xA01>;
 		};
 	};
+};
 
-	combiner: interrupt-controller@10440000 {
+&combiner {
 	samsung,combiner-nr = <18>;
-	};
+};
 
-	gic: interrupt-controller@10490000 {
+&gic {
 	cpu-offset = <0x8000>;
-	};
 };