frameworks/av: port fixes in LPA effects

-audio: Fix for deadlock issue during LPA playback.
-frameworks/av: Fix the LPA-AudioEffects dead lock issue CRs-Fixed: 477511
-audioflinger: Fix pops in LPA while effects are applied CRs-Fixed: 526799
-audioflinger: Fix delay in enabling effect for LPA CRs-Fixed: 525510

Change-Id: Id3702bbeb0212cbe92370416b83daf0e383d6e3c