arm64: dts: renesas: r8a77990: ebisu: Enable watchdog timer

Add a device node for the Watchdog Timer (WDT) controller on the
R8A77990 SoC, and enable the watchdog on the Ebisu board.
Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
[geert: Squashed 2 commits]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts

@@ -60,6 +60,11 @@ mux {
 	};
 };
 
+&rwdt {
+	timeout-sec = <60>;
+	status = "okay";
+};
+
 &scif2 {
 	status = "okay";
 };

arch/arm64/boot/dts/renesas/r8a77990.dtsi

@@ -60,6 +60,16 @@ soc: soc {
 		#size-cells = <2>;
 		ranges;
 
+		rwdt: watchdog@e6020000 {
+			compatible = "renesas,r8a77990-wdt",
+				     "renesas,rcar-gen3-wdt";
+			reg = <0 0xe6020000 0 0x0c>;
+			clocks = <&cpg CPG_MOD 402>;
+			power-domains = <&sysc 32>;
+			resets = <&cpg 402>;
+			status = "disabled";
+		};
+
 		gpio0: gpio@e6050000 {
 			compatible = "renesas,gpio-r8a77990",
 				     "renesas,rcar-gen3-gpio";