Revert "AudioEffect: Add a stereo widener effect"

This reverts commit b145407128dbc2bf71019861976b28d1672bc312.

Change-Id: I7d4edcf74aac855b955ea2eea0c905e2318256a6
Revert "AudioFX: Add center frequency param to bassboost"

This reverts commit 79620059d2e2f894ffc8bf7144bce7f8d7210549.

Change-Id: Ice783f8f1c8b5694dc3c56e5b897b0cdedfdc36a