Qualcomm SPMI Controller (PMIC Arbiter)

Required properties:
- cell-index : the bus identifier.
- compatible : should be "qcom,spmi-pmic-arb".
- reg-names  : should be "core", "intr", "cnfg"
- reg : offset and length of the PMIC Arbiter Core register map.
- reg : offset and length of the PMIC Arbiter Interrupt controller register map.
- reg : offset and length of the PMIC Arbiter Configuration register map.
- interrupts : the PMIC Arbiter interrupt.
- qcom,pmic-arb-ee : the execution environment (EE) identifier.
- qcom,pmic-arb-channel : the assigned channel number for channel registers.

Optional properties:
- qcom,not-wakeup : boolean property which indicates that SPMI PMIC interrupts
	should not be treated as wakeup sources
- reg-names  : may have "chnls", "obsrvr"
- reg : offset and length of the PMIC Arbiter Core Channels register map.
- reg : offset and length of the PMIC Arbiter Core Observer Channels reg map.
- qcom,pmic-arb-max-peripherals : the max supported peripheral channels on device
- qcom,pmic-arb-max-periph-interrupts : the max supported peripheral channels
					interrupts on device
- qcom,reserved-channel : channel number that this driver should not touch.
			  Used only for v2 hw.

Example:

	qcom,spmi@fc4c0000 {
		cell-index = <0>;
		compatible = "qcom,spmi-pmic-arb";
		reg-names = "core", "chnls", "obsrvr", "intr", "cnfg";
		reg = <0x200f000 0x1000>,
			<0x2400000 0x400000>,
			<0x2c00000 0x400000>,
			<0x3800000 0x200000>,
			<0x200a000 0x2100>;
		interrupts = <0 190 0>;
		qcom,pmic-arb-ee = <0>;
		qcom,pmic-arb-channel = <0>;
	};