Mediatek SoCs Watchdog timer

Required properties:

- compatible should contain:
	* "mediatek,mt2701-wdt" for MT2701 compatible watchdog timers
	* "mediatek,mt6589-wdt" for all compatible watchdog timers (MT2701,
		MT6589)

- reg : Specifies base physical address and size of the registers.

Example:

wdt: watchdog@010000000 {
	compatible = "mediatek,mt6589-wdt";
	reg = <0x10000000 0x18>;
};