hal: move audio specific config files to HAL

Move all audio specific config files
from device/qcom/msm8996 to
hardware/qcom/audio/configs/msm8996 folder.

Move all audio configurations from target specific
BoardConfigVendor.mk to target specific
makefile in hardware/qcom/audio/configs.
Move all audio related system properties from system.prop
to target specific makefile

Change-Id: I51a058c83f3047c42f2a21b0568366f2da9ce71c