Binding for Fairchild FAN53555 regulators

Required properties:
  - compatible: one of "fcs,fan53555", "silergy,syr827", "silergy,syr828",
    "halo,hl7509" or "halo,hl7503"
  - reg: I2C address

Optional properties:
  - fcs,suspend-voltage-selector: declare which of the two available
		voltage selector registers should be used for the suspend
		voltage. The other one is used for the runtime voltage setting
		Possible values are either <0> or <1>
  - vin-supply: regulator supplying the vin pin
  - fcs,disable-suspend: Boolean flag which specifies if suspend voltage
		configuration should be avoided. If this property is present,
		then the voltage selector register defined by
		fcs,suspend-voltage-selector should not be modified at runtime.

Example:

	regulator@40 {
		compatible = "fcs,fan53555";
		regulator-name = "fan53555";
		regulator-min-microvolt = <1000000>;
		regulator-max-microvolt = <1800000>;
		vin-supply = <&parent_reg>;
		fcs,suspend-voltage-selector = <1>;
	};

	regulator@60 {
		compatible = "halo,hl7509";
		regulator-name = "hl7509";
		regulator-min-microvolt = <600000>;
		regulator-max-microvolt = <1230000>;
		fcs,suspend-voltage-selector = <1>;
		fcs,disable-suspend;
	};