performance: Add Performance class and PerfLock API.

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

Conflicts:
	core/jni/Android.mk
	core/jni/AndroidRuntime.cpp

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.

performance: Add opcodes to limit maximum number of cores

Add opcodes to support the limiting of maximum
number of cores online.

performance: Add comments for CPU FREQ usage

Add comments to inform users on the CPU
frequencies PerfLock supports and usage.

Signed-off-by: xboxfanj <xboxfanj@msn.com>

Change-Id: Ibc7eaeb3c2b94abca1125786f73ea97201e41830