msm7x30: Remove local audio HAL

* We can have our own HAL in harware/qcom/audio-caf now

Squashed commit of the following reverts:

Revert "legacy/msm7x30: Enable stereo recording"

This reverts commit 00df1cf78ea2c7cd4407a5af969ca406b255d6f8.

Revert "msm7x30: Add local copy of audio HAL and build it"

This reverts commit 986463e6c4f2fe076c34676263c5d0b21d71cf6e.

Change-Id: I98e25fcf61bdb40d840a75806ee6011f555fc394