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 the 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-msm8953",
		"qcom,mpm-gic-msm8937",
		"qcom,mpm-gic-qcs405"
		"qcom,mpm-gic-trinket"
		"qcom,mpm-gic-mdm9607"
		"qcom,mpm-gic-sdm660"
		"qcom,mpm-gic-sdm429"

- 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-gic", "qcom,mpm-gic-msm8953";
	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>;
};


One to monitor the wakeup capable gpio interrupts called wakegpio.

properties:

- compatible:
	Usage: required
	Value type: <string>
	Definition: Should contain "qcom,mpm-gpio" and the respective target compatible flag
	from below ones.
		"qcom,mpm-gpio-msm8953",
		"qcom,mpm-gpio-msm8937",
		"qcom,mpm-gpio-qcs405"
		"qcom,mpm-gpio-trinket",
		"qcom,mpm-gpio-mdm9607"
		"qcom,mpm-gpio-sdm660"
		"qcom,mpm-gpio-sdm429"

- 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.

Example:

wakegpio: wake-gpio {
	compatible = "qcom,mpm-gpio", "qcom,mpm-gpio-msm8953";
	interrupt-controller;
	interrupt-parent = <&tlmm>;
	#interrupt-cells = <2>;
};