Hisilicon Hi655x Voltage regulators

Note:
The Hi655x regulator control is managed by Hi655x PMIC.
So the node of this regulator must be child node of Hi655x
PMIC node.

The driver uses the regulator core framework, so please also
take the bindings of regulator.txt for reference.

The valid names for regulators are:

LDO2_2V8 LDO7_SDIO LDO10_2V85 LDO13_1V8 LDO14_2V8
LDO15_1V8 LDO17_2V5 LDO19_3V0 LDO21_1V8 LDO22_1V2

Example:
        pmic: pmic@f8000000 {
                compatible = "hisilicon,hi655x-pmic";
		...
		regulators {
			ldo2: LDO2@a21 {
				regulator-name = "LDO2_2V8";
				regulator-min-microvolt = <2500000>;
				regulator-max-microvolt = <3200000>;
				regulator-enable-ramp-delay = <120>;
			};
			...
		}
	}
