* RPM Sleep Stats

RPM maintains sleep data in the RPM RAM. A device tree node is added
that will hold the address of the RPM RAM from where sleep stats are read.
Additionally a version number is added to distinguish the type of data
structure being read from the RAM.

RPM maintains free heap space availability in the RPM RAM. RPM free heap space
value is required for debugging purpose.

The required properties for rpm-stats are:

- compatible: "qcom,rpm-stats"
- reg: The address on the RPM RAM from where stats are read.

	Second register(optional) specifies the offset of the rpm
	stats start address pointer. If the second register is
	available, the offset value read is added to the first
	register address to read the stats.

	Third register(optional) specifies the offset of the rpm
	free heap space value.
- reg-names: Name given the register holding address.
- qcom,sleep-stats-version: Version number.

Example 1:

qcom,rpm-stats@fc19dbd0 {
		compatible = "qcom,rpm-stats";
		reg = <0xfc19dbd0 0x1000>;
		reg-names = "phys_addr_base";
		qcom,sleep-stats-version = <2>;
};

Example 2:

qcom,rpm-stats@fc000000 {
		compatible = "qcom,rpm-stats";
		reg = <0xfc000000 0x1000>,
			<0xfc190014 0x4>;
		reg-names = "phys_addr_base";
		qcom,sleep-stats-version = <2>;
};