Texas Instruments TWL family (twl4030) reset and power management module

The power management module inside the TWL family provides several facilities
to control the power resources, including power scripts. For now, the
binding only supports the complete shutdown of the system after poweroff.

Required properties:
- compatible : must be one of the following
	"ti,twl4030-power"
	"ti,twl4030-power-reset"

The use of ti,twl4030-power-reset is recommended at least on
3530 that needs a special configuration for warm reset to work.

Optional properties:
- ti,use_poweroff: With this flag, the chip will initiates an ACTIVE-to-OFF or
		   SLEEP-to-OFF transition when the system poweroffs.

Example:
&i2c1 {
	clock-frequency = <2600000>;

	twl: twl@48 {
		reg = <0x48>;
		interrupts = <7>; /* SYS_NIRQ cascaded to intc */
		interrupt-parent = <&intc>;

		twl_power: power {
			compatible = "ti,twl4030-power";
			ti,use_poweroff;
		};
	};
};