ARM: dts: rskrza1: add rtc DT support

Enable the realtime clock.
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r7s72100-rskrza1.dts

@@ -73,6 +73,10 @@ &ostm1 {
 	status = "okay";
 };
 
+&rtc {
+	status = "okay";
+};
+
 &scif2 {
 	status = "okay";
 };