ARM: dts: socfpga: Add labels for CPU nodes

This makes it easier to reference the CPU nodes afterwards.
Signed-off-by: Florian Vaussard <florian.vaussard@heig-vd.ch>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>

arch/arm/boot/dts/socfpga.dtsi

@@ -37,13 +37,13 @@ cpus {
 		#size-cells = <0>;
 		enable-method = "altr,socfpga-smp";
 
-		cpu@0 {
+		cpu0: cpu@0 {
 			compatible = "arm,cortex-a9";
 			device_type = "cpu";
 			reg = <0>;
 			next-level-cache = <&L2>;
 		};
-		cpu@1 {
+		cpu1: cpu@1 {
 			compatible = "arm,cortex-a9";
 			device_type = "cpu";
 			reg = <1>;