* Real Time Clock for Renesas SH and ARM SoCs

Required properties:
- compatible: Should be "renesas,r7s72100-rtc" and "renesas,sh-rtc" as a
  fallback.
- reg: physical base address and length of memory mapped region.
- interrupts: 3 interrupts for alarm, period, and carry.
- interrupt-names: The interrupts should be labeled as "alarm", "period", and
  "carry".
- clocks: The functional clock source for the RTC controller must be listed
  first (if exists). Additionally, potential clock counting sources are to be
  listed.
- clock-names: The functional clock must be labeled as "fck". Other clocks
  may be named in accordance to the SoC hardware manuals.


Example:
rtc: rtc@fcff1000 {
	compatible = "renesas,r7s72100-rtc", "renesas,sh-rtc";
	reg = <0xfcff1000 0x2e>;
	interrupts = <GIC_SPI 276 IRQ_TYPE_EDGE_RISING
		      GIC_SPI 277 IRQ_TYPE_EDGE_RISING
		      GIC_SPI 278 IRQ_TYPE_EDGE_RISING>;
	interrupt-names = "alarm", "period", "carry";
	clocks = <&mstp6_clks R7S72100_CLK_RTC>, <&rtc_x1_clk>,
		 <&rtc_x3_clk>, <&extal_clk>;
	clock-names = "fck", "rtc_x1", "rtc_x3", "extal";
};