Merge changes from topic "discard" into oc-dev

* changes:
  [automerger] [DO NOT MERGE] make_f2fs: issue discard commands on mkfs am: 17705ce009 am: 5035821535 skipped: d03107eda1
  [automerger] [DO NOT MERGE] make_f2fs: issue discard commands on mkfs am: 17705ce009 am: 5035821535
  [automerger] [DO NOT MERGE] make_f2fs: issue discard commands on mkfs am: 17705ce009
  [DO NOT MERGE] make_f2fs: issue discard commands on mkfs