Driver for part of pm8916 PMIC - gpio and power/reset keys

This device should be child of SPMI pmic.

1) GPIO driver

Required properties:
- compatible: "qcom,pm8916-gpio"
- reg: peripheral ID, size of register block
- gpio-controller
- gpio-count: number of GPIOs
- #gpio-cells: 2

Optional properties:
- gpio-bank-name: name of bank (as default "pm8916" is used)

Example:

pmic_gpios: gpios@c000 {
	compatible = "qcom,pm8916-gpio";
	reg = <0xc000 0x400>;
	gpio-controller;
	gpio-count = <4>;
	#gpio-cells = <2>;
	gpio-bank-name="pmic";
};


2) Power/Reset key driver

Required properties:
- compatible: "qcom,pm8916-pwrkey"
- reg: peripheral ID, size of register block
- gpio-controller
- #gpio-cells: 2

Optional properties:
- gpio-bank-name: name of bank (as default "pm8916_key" is used)


Example:

pmic_pon: pon@800 {
	compatible = "qcom,pm8916-pwrkey";
	reg = <0x800 0x96>;
	#gpio-cells = <2>;
	gpio-controller;
};