Ingenic Watchdog Timer (WDT) Controller for JZ4740 & JZ4780

Required properties:
compatible: "ingenic,jz4740-watchdog" or "ingenic,jz4780-watchdog"
reg: Register address and length for watchdog registers
clocks: phandle to the RTC clock
clock-names: should be "rtc"

Example:

watchdog: jz4740-watchdog@10002000 {
	compatible = "ingenic,jz4740-watchdog";
	reg = <0x10002000 0x10>;

	clocks = <&cgu JZ4740_CLK_RTC>;
	clock-names = "rtc";
};