ARM: dts: r8a7742-iwg21d-q7: Add RWDT support

Enable RWDT and use 60 seconds as default timeout.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@bp.renesas.com>
Link: https://lore.kernel.org/r/1590420129-7531-5-git-send-email-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm/boot/dts/r8a7742-iwg21d-q7.dts

@@ -90,6 +90,11 @@
 	};
 };
 
+&rwdt {
+	timeout-sec = <60>;
+	status = "okay";
+};
+
 &scifa2 {
 	pinctrl-0 = <&scifa2_pins>;
 	pinctrl-names = "default";