Revert "audio_effects: Add stereowide effect"

This reverts commit bd4e0f99abf6e0d391d46d18fe264de1e5186e5f.
mako: enable echo cancellation for voice communication

This greatly improves the quality of VoIP calls, tested on the app
"LINE". Without this, the other party will be able to hear echo
of their own voice.

Reference: http://source.android.com/devices/audio_implement.html#preprocessing

Change-Id: Id0ccb732778ecc8d4c9e140249ec230654f351cc