8960: Fix proxy channel count setup

I9660e3088bc747c30891b0aa7ec8d22096dd0fa2 changed the method, but
applied the changes only to 8974. fixit

Change-Id: I3cd36eb80732ec9f6f8274153c4ac7cd799c3aec
msm7x30: Sync audio_policy with alsa_sound

Change-Id: I8be0110f566c8f91d6a736471eaf614184cd0faa