ARM: at91/at91-ariag25.dts: add RTC node

Reported-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/boot/dts/at91-ariag25.dts

@@ -138,6 +138,10 @@
 					};
 				};
 			};
+
+			rtc@fffffeb0 {
+				status = "okay";
+			};
 		};
 
 		usb0: ohci@00600000 {