audio/msm7x30: Fix for Echo in Gtalk

- Echo is observed in Gtalk.
- Audio HAL informs that clients that it handle the Echo
  cancellation and with AHAL client turns off the EC.
- EC is not supported in this PL remove it from getparam
CRs-Fixed: 427161

Change-Id: I62eba7ed7566045f61c34a51c8ac36029b8596ea