ARM: dts: silk: Enable watchdog support

Enable the watchdog, so the board can be restarted by a watchdog
timeout.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7794-silk.dts

@@ -540,6 +540,11 @@ dai0 {
 	};
 };
 
+&rwdt {
+	timeout-sec = <60>;
+	status = "okay";
+};
+
 &ssi1 {
 	shared-pin;
 };