Renesas Watchdog Timer (WDT) Controller

Required properties:
- compatible : Should be "renesas,r8a7795-wdt", or "renesas,rcar-gen3-wdt"

  When compatible with the generic version, nodes must list the SoC-specific
  version corresponding to the platform first, followed by the generic
  version.

- reg : Should contain WDT registers location and length
- clocks : the clock feeding the watchdog timer.

Optional properties:
- timeout-sec : Contains the watchdog timeout in seconds
- power-domains : the power domain the WDT belongs to

Examples:

	wdt0: watchdog@e6020000 {
		compatible = "renesas,r8a7795-wdt", "renesas,rcar-gen3-wdt";
		reg = <0 0xe6020000 0 0x0c>;
		clocks = <&cpg CPG_MOD 402>;
		power-domains = <&cpg>;
		timeout-sec = <60>;
	};