audio: Fixup BT A2DP for QCOM A-family

A- Family doesn't support separate output for a2dp , removed the
getA2dpOutput(). getDeviceForStrategy() is selecting the proper
device using mA2dpSuspended flag.

Change-Id: I0721e5cb9943f888645f6220334ee6707df96e0b
Merge branch 'cm-12.0' of git://github.com/CyanogenMod/android_frameworks_av into cm-12.0