MFC: r249203 (partial)

- Make ata_str2mode() static, it's not used outside of ata-all.c.
- Move ata_timeout() to ata-all.c so we don't need to expose both this
  function and ata_cam_end_transaction() but only the former.
- Move ata_cmd2str() from ata-queue.c to ata-all.c.
- Add some missing prototypes.


git-svn-id: svn://svn.freebsd.org/base/stable/9@251224 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Merge remote-tracking branch 'upstream/svn_stable_9' into svn_stable_9