MSM Core Energy Aware driver

The Energy Aware driver provides per core power and temperature
information to the scheduler for it to make more power efficient
scheduling decision.

The required nodes for the Energy-aware driver are:

- compatible:    "qcom,apss-core-ea"

Required properties:
- qcom,core-mapping: Parent node that lists characteristics of
                 the cpus. Requires the child node for each
                 cpu.

Optional properties:
- qcom,low-hyst-temp: Degrees C below which the power numbers
                 need to be recomputed for the cores and reset
                 the threshold. If this is not present, the default
                 value is 10C.
- qcom,high-hyst-temp: Degrees C above which the power numbers
                 need to be recomputed for the cores and reset
                 the threshold. If this property is not present,
                 the default value is 5C.
- qcom,polling-interval: Interval for which the power numbers
                 need to be recomputed for the cores if there
                 is no change in threshold. If this property is not
                 present, the power is recalculated only on
                 temperature threshold notifications.

[Second level nodes]
Required properties to define per core characteristics:
- qcom,cpu-name: CPU phandle to read the mpidr value

Optional properties to define per core characteristics:
- qcom,sensor:  Sensor phandle to map a particular sensor to the core.
                If this property is not present, then the core is assumed
                to be at 40C for all the power estimations. No sensor
                threshold is set.

Example

qcom,msm-core {
	compatible = "qcom,apss-core-ea";
	qcom,low-hyst-temp = <10>;
	qcom,high-hyst-temp = <5>;
	qcom,polling-interval = <50>;

	qcom,core-mapping {
		qcom,cpu0-chars {
			qcom,sensor = <&sensor_information0>;
			qcom,cpu-name = <&CPU0>;
		};

		qcom,cpu1-chars {
			qcom,sensor = <&sensor_information1>;
			qcom,cpu-name = <&CPU1>;
		};

		qcom,cpu2-chars {
			qcom,sensor = <&sensor_information2>;
			qcom,cpu-name = <&CPU2>;
		};

		qcom,cpu3-chars {
			qcom,sensor = <&sensor_information3>;
			qcom,cpu-name = <&CPU3>;
		};
	};
};

