Hisilicon RTC controller

Required properties:
-compatible: should contain one SoC specific compatible string
The SoC specific strings supported including:
- compatible: "hisilicon,hi35xvr-rtc"
- reg: physical base address and length of the controller's registers.
- interrupts: IRQ line for the RTC.

Example:
rtc: rtc@120b0000 {
		 compatible = "hisilicon,hi35xvr-rtc";
		 reg = <0x120b0000 0x10000>;
		 interrupts = <0 5 4>;
	 };

