Revert "Fsync Toggle"

This reverts commit b48363c87aaf19321d174f7a377562e61cb3845b.
Revert "Revert "fs/dyn_sync_cntrl: dynamic sync control""

This reverts commit a8718c929d6ba167b995b78e8373e9144daf26cc.
Revert "Revert "Asynchronous Fsync: initial extraction of Async Fsync from HTC""

This reverts commit 45489588487eebddf76a7c79f70d704907a60f48.