performance: Add Performance class and PerfLock API.

New Performance class with PerfLock APIs to allow
system level performance optimizations to be toggled.

Credit Vince Leung
performance: Add concurrency and timer support to PerfLock.

Add timer and concurrency support to PerfLock APIs.
Update optimization codes.
Removed cpuBoost API.
Add setCpuBoost API.

Change-Id: I1deea3713a3ea79972b9cfb245e594712b57ca26