mvebu: supress useless in-cpu rtc init on the Mamba

Signed-off-by: Imre Kaloz <kaloz@openwrt.org>

SVN-Revision: 45704

target/linux/mvebu/patches-3.18/004-mamba_disable_rtc.patch

@@ -0,0 +1,14 @@
+--- a/arch/arm/boot/dts/armada-xp-linksys-mamba.dts
++++ b/arch/arm/boot/dts/armada-xp-linksys-mamba.dts
+@@ -183,6 +183,11 @@
+ 
+ 		internal-regs {
+ 
++			rtc@10300 {
++				/* No crystal connected to the internal RTC */
++				status = "disabled";
++			};
++
+ 			/* J10: VCC, NC, RX, NC, TX, GND  */
+ 			serial@12000 {
+ 				status = "okay";