arm64: dts: renesas: Unify the labels for RWDT

The labels for RWDT device node were named as 2 types now:

 - wdt0: r8a7795, r8a7796, r8a77965.
 - rwdt: r8a77970, r8a77990, r8a77995.

To be made consistent, this patch unifis the labels as the hardware
name "rwdt".
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/boot/dts/renesas/r8a7795.dtsi

@@ -288,7 +288,7 @@ soc: soc {
 		#size-cells = <2>;
 		ranges;
 
-		wdt0: watchdog@e6020000 {
+		rwdt: watchdog@e6020000 {
 			compatible = "renesas,r8a7795-wdt", "renesas,rcar-gen3-wdt";
 			reg = <0 0xe6020000 0 0x0c>;
 			clocks = <&cpg CPG_MOD 402>;

arch/arm64/boot/dts/renesas/r8a7796.dtsi

@@ -266,7 +266,7 @@ soc {
 		#size-cells = <2>;
 		ranges;
 
-		wdt0: watchdog@e6020000 {
+		rwdt: watchdog@e6020000 {
 			compatible = "renesas,r8a7796-wdt",
 				     "renesas,rcar-gen3-wdt";
 			reg = <0 0xe6020000 0 0x0c>;

arch/arm64/boot/dts/renesas/r8a77965.dtsi

@@ -138,7 +138,7 @@ soc {
 		#size-cells = <2>;
 		ranges;
 
-		wdt0: watchdog@e6020000 {
+		rwdt: watchdog@e6020000 {
 			compatible = "renesas,r8a77965-wdt",
 				     "renesas,rcar-gen3-wdt";
 			reg = <0 0xe6020000 0 0x0c>;

arch/arm64/boot/dts/renesas/salvator-common.dtsi

@@ -850,7 +850,7 @@ &vin7 {
 	status = "okay";
 };
 
-&wdt0 {
+&rwdt {
 	timeout-sec = <60>;
 	status = "okay";
 };

arch/arm64/boot/dts/renesas/ulcb.dtsi

@@ -444,7 +444,7 @@ &usb2_phy1 {
 	status = "okay";
 };
 
-&wdt0 {
+&rwdt {
 	timeout-sec = <60>;
 	status = "okay";
 };