ARM: dts: rmobile: Add soc label to Gen3

Add label to the /soc node, so it can be referenced from the U-Boot DTs.
Signed-off-by: NMarek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
---
V2: Rebase on u-boot/master

arch/arm/dts/r8a7796.dtsi

@@ -259,7 +259,7 @@
 		clock-frequency = <0>;
 	};
 
-	soc {
+	soc: soc {
 		compatible = "simple-bus";
 		interrupt-parent = <&gic>;
 		#address-cells = <2>;

arch/arm/dts/r8a77965.dtsi

@@ -144,7 +144,7 @@
 				     <&a57_1>;
 	};
 
-	soc {
+	soc: soc {
 		compatible = "simple-bus";
 		interrupt-parent = <&gic>;
 		#address-cells = <2>;

arch/arm/dts/r8a77970.dtsi

@@ -72,7 +72,7 @@
 		clock-frequency = <0>;
 	};
 
-	soc {
+	soc: soc {
 		compatible = "simple-bus";
 		interrupt-parent = <&gic>;
 

arch/arm/dts/r8a77995.dtsi

@@ -66,7 +66,7 @@
 		clock-frequency = <0>;
 	};
 
-	soc {
+	soc: soc {
 		compatible = "simple-bus";
 		interrupt-parent = <&gic>;
 		#address-cells = <2>;