Renesas Watchdog Timer (WDT) Controller

Required properties:
- compatible : Should be "renesas,<soctype>-wdt", and
	       "renesas,rcar-gen3-wdt" or "renesas,rza-wdt" as fallback.
	       Examples with soctypes are:
	         - "renesas,r7s72100-wdt" (RZ/A1)
	         - "renesas,r8a7795-wdt" (R-Car H3)
	         - "renesas,r8a7796-wdt" (R-Car M3-W)
	         - "renesas,r8a77970-wdt" (R-Car V3M)
	         - "renesas,r8a77995-wdt" (R-Car D3)

  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
- interrupts: Some WDTs have an interrupt when used in interval timer mode

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>;
	};