TI LP873X PMIC MFD driver

Required properties:
  - compatible:	"ti,lp8732", "ti,lp8733"
  - reg:		I2C slave address.
  - gpio-controller:	Marks the device node as a GPIO Controller.
  - #gpio-cells:	Should be two.  The first cell is the pin number and
			the second cell is used to specify flags.
			See ../gpio/gpio.txt for more information.
  - xxx-in-supply:	Phandle to parent supply node of each regulator
			populated under regulators node. xxx can be
			buck0, buck1, ldo0 or ldo1.
  - regulators:	List of child nodes that specify the regulator
			initialization data.
Example:

pmic: lp8733@60 {
	compatible = "ti,lp8733";
	reg = <0x60>;
	gpio-controller;
	#gpio-cells = <2>;

	buck0-in-supply = <&vsys_3v3>;
	buck1-in-supply = <&vsys_3v3>;
	ldo0-in-supply = <&vsys_3v3>;
	ldo1-in-supply = <&vsys_3v3>;

	regulators {
		lp8733_buck0: buck0 {
			regulator-name = "lp8733-buck0";
			regulator-min-microvolt = <800000>;
			regulator-max-microvolt = <1400000>;
			regulator-min-microamp = <1500000>;
			regulator-max-microamp = <4000000>;
			regulator-ramp-delay = <10000>;
			regulator-always-on;
			regulator-boot-on;
		};

		lp8733_buck1: buck1 {
			regulator-name = "lp8733-buck1";
			regulator-min-microvolt = <800000>;
			regulator-max-microvolt = <1400000>;
			regulator-min-microamp = <1500000>;
			regulator-max-microamp = <4000000>;
			regulator-ramp-delay = <10000>;
			regulator-boot-on;
			regulator-always-on;
		};

		lp8733_ldo0: ldo0 {
			regulator-name = "lp8733-ldo0";
			regulator-min-microvolt = <800000>;
			regulator-max-microvolt = <3000000>;
			regulator-boot-on;
			regulator-always-on;
		};

		lp8733_ldo1: ldo1 {
			regulator-name = "lp8733-ldo1";
			regulator-min-microvolt = <800000>;
			regulator-max-microvolt = <3000000>;
			regulator-always-on;
			regulator-boot-on;
		};
	};
};