[SCSI] bfa: Add support to store driver configuration in flash.

- Added dconf (Driver Config) BFA sub-module.
- The dconf sub-module provides interfaces and manages flash writes
  to the flash DRV parition.
- dconf sub-module also ensures that the whole 64K DRV partition is updated
  on a flash write.

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