Texas Instruments OMAP compatible voltage domain description

This binding uses [1] and describes the voltage domain devices
typically used on Texas Instruments OMAP compatible SoC family of
processors.

[1] Documentation/devicetree/bindings/power/voltdm/voltage_domain.txt

Required Properties:
- compatible: Should be one of:
	"ti,omap-voltdm" - basic voltage domain controlling VDD and VBB
	"ti,omap5-voltdm" - OMAP5+ optimized voltages in efuse(class0)VDD
			    along with VBB
	"ti,omap5-core-voltdm" - OMAP5+ optimized voltages in efuse(vlass0) VDD
			    but no VBB.
- vdd-supply: phandle to regulator controlling VDD supply
- vbb-supply: phandle to regulator controlling Body Bias supply (optional if
  "ti,omap5-core-voltdm")
  (Usually Adaptive Body Bias regulator)
- #voltdm-cells: shall be <0>
- reg: Address and length of the efuse register set for the device (mandatory
	only for "ti,omap5-voltdm")
- ti,efuse-settings: An array of u32 tuple items providing information about
	optimized efuse configuration. Each item consists of the following:
	volt: voltage in uV - reference voltage (OPP voltage)
	efuse_offseet: efuse offset from reg where the optimized voltage is stored.

Optional Properties:
- ti,absolute-max-voltage-uv: absolute maximum voltage for the voltage domain.

Example:
voltage_domain_mpu: voltdm@1 {
	compatible = "ti,omap-voltdm";
	#voltdm-cells = <0>;

	vdd-supply = <&vcc>;
	vbb-supply = <&abb_mpu>;
};

voltdm_mpu: voltdm@4a003b20 {
	compatible = "ti,omap5-voltdm";
	#voltdm-cells = <0>;
	vdd-supply = <&vcc>;
	vbb-supply = <&abb_mpu>;
	reg = <0x4a003b20 0x8>;
	ti,efuse-settings = <
	/* uV   offset */
	1060000 0x0
	1160000 0x4
	1210000 0x8
	>;
};

voltdm_core: voltdm@4a003d20 {
	compatible = "ti,omap5-core-voltdm";
	#voltdm-cells = <0>;
	vdd-supply = <&smps4>;
	reg = <0x4a003b20 0x4>;
	ti,efuse-settings = <
	/* uV   offset */
	1060000 0x0
	>;
};
