Rockchip cpu avs device tree bindings
-------------------------------------

Under the same frequency, the operating voltage tends to decrease with
increasing leakage. so it is necessary to adjust opp's voltage according
to leakage for power.


Required properties:
- cluster-id: At runtime, the platform can find a cpu's cluster_id
  according to it's cpu_id and match cluster-id property.
- min-volt: The minimum voltage in uV. Even though opp's voltage will be
  adjusted, it must be bigger than or equal to the minimum.
- min-freq: The minimum frequency in KHz. If an opp's frequency is bigger
  than or equal to the minimum, its volatge will be adjusted.
- leakage-adjust-volt: The property is an array of 3-tuples items, and
  each item consists of leakage and voltage like
  <min-leakage-mA max-leakage-mA volt-uV>.
	min-leakage: minimum leakage in mA, ranges from 0 to 254.
	max-leakage: maximum leakage in mA, ranges from 0 to 254.
	volt: voltage offset in uV to apply to the opp table entries.
- nvmem-cells: A phandle to the leakage data provided by efuse.
- nvmem-cell-names: Should be "cpu_leakage".

Example:

	cpu_avs: cpu-avs {
		cluster0-avs {
			cluster-id = <0>;
			min-volt = <800000>; /* uV */
			min-freq = <408000>; /* KHz */
			leakage-adjust-volt = <
			/*  mA        mA         uV */
			    0         254        0
			>;
			nvmem-cells = <&cpul_leakage>;
			nvmem-cell-names = "cpu_leakage";
		};
		cluster1-avs {
			cluster-id = <1>;
			min-volt = <800000>; /* uV */
			min-freq = <408000>; /* KHz */
			leakage-adjust-volt = <
			/*  mA        mA         uV */
			    0         254        0
			>;
			nvmem-cells = <&cpub_leakage>;
			nvmem-cell-names = "cpu_leakage";
		};
	};