ST-Ericsson COH 901 331 Real Time Clock

Required properties:
- compatible: must be "stericsson,coh901331"
- reg: address range of rtc register set.
- interrupt-parent: phandle for the interrupt controller.
- interrupts: rtc alarm interrupt.
- clocks: phandle to the rtc clock source

Example:
	rtc: rtc@c0017000 {
		compatible = "stericsson,coh901331";
		reg = <0xc0017000 0x1000>;
		interrupt-parent = <&vicb>;
		interrupts = <10>;
		clocks = <&rtc_clk>;
	};