Devfreq CPUfreq governor

devfreq-cpufreq is a parent device that contains one or more child devices.
Each child device provides CPU frequency to device frequency mapping for a
specific device. Examples of devices that could use this are: DDR, cache and
CCI.

Parent device name shall be "devfreq-cpufreq".

Required child device properties:
- cpu-to-dev-map, or cpu-to-dev-map-<X>:
			A list of tuples where each tuple consists of a
			CPU frequency (KHz) and the corresponding device
			frequency. CPU frequencies not listed in the table
			will use the device frequency that corresponds to the
			next rounded up CPU frequency.
			Use "cpu-to-dev-map" if all CPUs in the system should
			share same mapping.
			Use cpu-to-dev-map-<cpuid> to describe different
			mappings for different CPUs. The property should be
			listed only for the first CPU if multiple CPUs are
			synchronous.
- target-dev:		Phandle to device that this mapping applies to.

Example:
	devfreq-cpufreq {
		cpubw-cpufreq {
			target-dev = <&cpubw>;
			cpu-to-dev-map =
				<  300000  1144 >,
				<  422400  2288 >,
				<  652800  3051 >,
				<  883200  5996 >,
				< 1190400  8056 >,
				< 1497600 10101 >,
				< 1728000 12145 >,
				< 2649600 16250 >;
		};

		cache-cpufreq {
			target-dev = <&cache>;
			cpu-to-dev-map =
				<  300000  300000 >,
				<  422400  422400 >,
				<  652800  499200 >,
				<  883200  576000 >,
				<  960000  960000 >,
				< 1497600 1036800 >,
				< 1574400 1574400 >,
				< 1728000 1651200 >,
				< 2649600 1728000 >;
		};
	};