QTI MPM interrupt controller
MPM (MSM sleep Power Manager) is QTI's platform parent
interrupt controller. It manages subsystem wakeups and
resources during sleep. This driver marks the wakeup
interrupts in APSS such that it monitors the interrupts
when the system is asleep, wakes up the APSS when one
of these interrupts occur and replays it to the subsystem
interrupt controller after it becomes operational.

Platform interrupt controller MPM is next in hierarchy,
followed by others.

This defines 2 interrupt controllers to monitor the
interrupts when system is asleep:

One to monitor the wakeup capable gic interrupts called
wakegic.

Properties:

- compatible:
	Usage: required
	Value type: <string>
	Definition: Should contain "qcom,mpm-gic" and the respective
	target compatible flag from below ones.
		"qcom,mpm-gic-holi"

- interrupts:
	Usage: required
	Value type: <prop-encoded-array>
	Definition: should specify the IRQ used by remote processor to
	wakeup APSS.

- interrupt-parent:
	Usage: required
	Value type: <phandle>
	Definition: Specifies the interrupt parent necessary for
	hierarchical domain to operate.

- interrupt-controller:
	Usage: required
	Value type: <bool>
	Definition: Identifies the node as an interrupt controller.

- reg:
	Usage: required
	Value type: <prop-encoded-array>
	Definition: Specifies the base physical address to trigger an
	interrupt into remote processor.

-reg-names:
	Usage: required
	Value type: <string>, <string>
	Definition: Specifies the address field names.

- qcom,num-mpm-irqs:
	Usage: optional
	Value type: <value>
	Defination: Specifies the number of interrupts supported.

Example:

wakegic: wake-gic@7781b8 {
	compatible = "qcom,mpm", "qcom,mpm-gic-holi";
	interrupts = <GIC_SPI 171 IRQ_TYPE_EDGE_RISING>;
	reg = <0x601d4 0x1000>,
	    <0xb011008 0x4>;  /* MSM_APCS_GCC_BASE 4K */
	reg-names = "vmpm", "ipc";
	interrupt-controller;
	interrupt-parent = <&intc>;
	#interrupt-cells = <3>;
};
