Qualcomm Global Distributed Switch Controller (GDSC) Regulator Driver

The GDSC driver, implemented under the regulator framework, is responsible for
safely collapsing and restoring power to peripheral cores on chipsets like
msm8974 for power savings.

Required properties:
 - compatible:      Must be "qcom,gdsc"
 - regulator-name:  A string used as a descriptive name for regulator outputs
 - reg:             The address of the GDSCR register

Optional properties:
 - parent-supply:   phandle to the parent supply/regulator node
 - qcom,clock-names: List of string names for core clocks
 - qcom,retain-mem:  Presence denotes a hardware requirement to leave the
		     forced core memory retention signals in the core's clock
		     branch control registers asserted.
 - qcom,retain-periph: Presence denotes a hardware requirement to leave the
		     forced periph memory retention signal in the core's clock
		     branch control registers asserted.
 - qcom,skip-logic-collapse: Presence denotes a requirement to leave power to
                             the core's logic enabled.

Example:
	gdsc_oxili_gx: qcom,gdsc@fd8c4024 {
		compatible = "qcom,gdsc";
		regulator-name = "gdsc_oxili_gx";
		parent-supply = <&pm8841_s4>;
		reg = <0xfd8c4024 0x4>;
		qcom,clock-names = "core_clk";
	};