NXP LPC1788 real-time clock

The LPC1788 RTC provides calendar and clock functionality
together with periodic tick and alarm interrupt support.

Required properties:
- compatible	: must contain "nxp,lpc1788-rtc"
- reg		: Specifies base physical address and size of the registers.
- interrupts	: A single interrupt specifier.
- clocks	: Must contain clock specifiers for rtc and register clock
- clock-names	: Must contain "rtc" and "reg"
  See ../clocks/clock-bindings.txt for details.

Example:
rtc: rtc@40046000 {
	compatible = "nxp,lpc1788-rtc";
	reg = <0x40046000 0x1000>;
	interrupts = <47>;
	clocks = <&creg_clk 0>, <&ccu1 CLK_CPU_BUS>;
	clock-names = "rtc", "reg";
};