ARM AMBA Primecell SP805 Watchdog

SP805 WDT is a ARM Primecell Peripheral and has a standard-id register that
can be used to identify the peripheral type, vendor, and revision.
This value can be used for driver matching.

As SP805 WDT is a primecell IP, it follows the base bindings specified in
'arm/primecell.txt'

Required properties:
- compatible:  Should be "arm,sp805" & "arm,primecell"
- reg:         Should contain location and length for watchdog timer register
- clocks:      Clocks driving the watchdog timer hardware. This list should be
               2 clocks. With 2 clocks, the order is wdog_clk, apb_pclk
               wdog_clk can be equal to or be a sub-multiple of the apb_pclk
               frequency
- clock-names: Shall be "wdog_clk" for first clock and "apb_pclk" for the
               second one

Optional properties:
- interrupts:  Should specify WDT interrupt number
- timeout-sec: Should specify default WDT timeout in seconds. If unset, the
               default timeout is determined by the driver

Example:
	watchdog@66090000 {
		compatible = "arm,sp805", "arm,primecell";
		reg = <0x66090000 0x1000>;
		interrupts = <GIC_SPI 406 IRQ_TYPE_LEVEL_HIGH>;
		clocks = <&wdt_clk>, <&apb_pclk>;
		clock-names = "wdog_clk", "apb_pclk";
	};