power: keep two cores online when display is on

This change is specific to 8084 and has been
modeled based on 8974 pro changes. Use PerfLock
to keep two cores online when the display is on.

Change-Id: Iffea0f9afbb3743cec2804da5884ec6d977b662a
power: Add apq8084 specific changes

Added compilation flag for power-8084.c in
makefile and detection of apq8084 soc id in
power.c.

Change-Id: I00e8e18f6de4ee7b38269e4bf565954db46148c5
power: Add support for POWER_HINT_LOW_POWER

 * Just call set_power_profile
 * Also clean up all the warnings

Change-Id: Ia42badac37815e29411ad135716a0f791a00c510