* SBSA (Server Base System Architecture) Generic Watchdog

The SBSA Generic Watchdog Timer is used to force a reset of the system
after two stages of timeout have elapsed.  A detailed definition of the
watchdog timer can be found in the ARM document: ARM-DEN-0029 - Server
Base System Architecture (SBSA)

Required properties:
- compatible: Should at least contain "arm,sbsa-gwdt".

- reg: Each entry specifies the base physical address of a register frame
  and the length of that frame; currently, two frames must be defined,
  in this order:
  1: Watchdog control frame;
  2: Refresh frame.

- interrupts: Should contain the Watchdog Signal 0 (WS0) SPI (Shared
  Peripheral Interrupt) number of SBSA Generic Watchdog.

Optional properties
- timeout-sec: Watchdog timeout values (in seconds).

Example for FVP Foundation Model v8:

watchdog@2a440000 {
	compatible = "arm,sbsa-gwdt";
	reg = <0x0 0x2a440000 0 0x1000>,
	      <0x0 0x2a450000 0 0x1000>;
	interrupts = <0 27 4>;
	timeout-sec = <30>;
};