arm64: dts: m3ulcb: enable WDT

This supports watchdog timer for M3ULCB board

Signed-off-by: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/boot/dts/renesas/r8a7796-m3ulcb.dts

@@ -90,3 +90,8 @@
 	clock-frequency = <14745600>;
 	status = "okay";
 };
+
+&wdt0 {
+	timeout-sec = <60>;
+	status = "okay";
+};