QTI Virtual SPMI controller (Virtual PMIC Arbiter)

The Virtual SPMI PMIC Arbiter is a frontend proxy based on backend virtual device.

Required properties:
- compatible : should be "qcom,virtspmi-pmic-arb".
- reg-names  : must contain:
     "core" - core registers

- reg : address + size pairs describing the Virtual PMIC arb register sets;
        order must correspond with the order of entries in reg-names
- #address-cells : must be set to 2
- #size-cells : must be set to 0

Example Virtual PMIC-Arbiter:

	spmi {
		compatible = "qcom,virtspmi-pmic-arb";
		reg-names = "core";
		reg = <0xfc4cf000 0x1000>;

		#address-cells = <2>;
		#size-cells = <0>;
	};
