[SCSI] bfa: Added HBA diagnostics support.

- Added diagnostics sub-module to BFA.
- Implemented interface to perform memtest/loopback test
  and some other diagnostics tests.

Signed-off-by: Krishna Gudipati <kgudipat@brocade.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>