powerhal: add opcode to disable sync on thread migration

Add and use the opcode to disable synchronization
of cores on foreground thread migration.
Synchronization of cores on foreground thread migration
feature is on by default so we will disable
when the display is off and encode/decode hints.

Change-Id: Ib52b894059b030b9a711c98e0dab41793c99276f
3 files changed