CPUSettings: make thermal daemon respect user preferences

Rework of "Add DevicePerformanceSettingsHelper" by Emerson Pinter

Depends on kernel patches by Emerson Pinter:
	- msm_thermal: limit cpu frequency for monitor
	- msm_thermal: make thermal_max_freq parameter writable

Change-Id: Iafc342f580c4adca668233bbc034cca4c63a97eb