power: Add new power hints

 * New hint to support CPU boosting with a duration.

Change-Id: I79b5a33814f2dbeaa033c950264d430876505175

libhardware: Add audio power hint

Change-Id: I5b03cc060356da23b6941c5937ef217c70dbf6dd

libhardware: Add power hint to set profile

 * A PowerHAL can implement support for this hint to receive
   power profile changes from the framework.

Change-Id: Ie1e9e3b827c731cf5a817a0491677e3451fe8678