Merge official F2FS git

Change-Id: Ie409060b195877907fb1c9fcb93de120e63ca19a
Revert "Merge official F2FS git"

This reverts commit 2bf42b82bebab00b4f6908a8fece46e50911ee9f.
Revert "Convert /data to F2FS"

This reverts commit cace08369cd2b3f49f02bbabbeef338bdfbe7812.