Mediatek SoCs Watchdog timer

Required properties:

- compatible should contain:
	* "mediatek,mt2701-wdt" for MT2701 compatible watchdog timers
	* "mediatek,mt7623-wdt" for MT7623 compatible watchdog timers
	* "mediatek,mt8521p-wdt" for MT8521p compatible watchdog timers
	* "mediatek,mt6589-wdt" for all compatible watchdog timers (MT2701,
		MT7623, MT6589 and MT8521p)

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

Example:

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