ZTE zx2967 Watchdog timer

Required properties:

- compatible : should be one of the following.
       * zte,zx296718-wdt
- reg : Specifies base physical address and size of the registers.
- clocks : Pairs of phandle and specifier referencing the controller's clocks.
- resets : Reference to the reset controller controlling the watchdog
           controller.

Optional properties:

- timeout-sec : Contains the watchdog timeout in seconds.
- zte,wdt-reset-sysctrl : Directs how to reset system by the watchdog.
	if we don't want to restart system when watchdog been triggered,
	it's not required, vice versa.
	It should include following fields.
	  * phandle of aon-sysctrl.
	  * offset of register that be written, should be 0xb0.
	  * configure value that be written to aon-sysctrl.
	  * bit mask, corresponding bits will be affected.

Example:

wdt: watchdog@1465000 {
	compatible = "zte,zx296718-wdt";
	reg = <0x1465000 0x1000>;
	clocks = <&topcrm WDT_WCLK>;
	resets = <&toprst 35>;
	zte,wdt-reset-sysctrl = <&aon_sysctrl 0xb0 1 0x115>;
};