cam/ata: Postpone removal of two compat sysctls until 15
Prefer UNMAPPEDIO and ROTATING from flags sysctl. See
- aeab0812e68c (Add flags sysctl to ada)
- cf3ff63e55e4 (Convert unmappedio over to a flag)
- 96eb32bf0f5a (Convert rotating to a flag bit)
Reviewed by: imp, ken, cam
Approved by: re (gjb)
MFC after: immediately (we want this in 14.0)
Differential Revision: https://reviews.freebsd.org/D42402
(cherry picked from commit d24729b2fd66a87c2b925b0c30e46bb0a9d6446a)
(cherry picked from commit fb288d493989d9df4c4f9c8eb3d7e28af61f8302)