audio: build hal from source
taken from p760 with minor modifications
https://github.com/CyanogenMod/android_device_lge_p760/blob/cm-10.1/audio/audio_hw.c
use ril additions from p760
https://github.com/CyanogenMod/android_device_lge_p760/blob/cm-10.1/ril/telephony/java/com/android/internal/telephony/U2RIL.java