Revert "msm8660-common: don't use prebuilt audio_policy.conf"

This reverts commit 88f74b81e64302386d9c9f3224a452d22a931045.
Revert "msm8660-common: use CAF QCOM Audio variant"

This reverts commit ac31ad1a694d72bfacce21de75905f85b28a71ef.