[SCSI] bfa: Add support to configure trunking on Brocade adapter ports.

- Added logic to enable / disable trunking on Brocade adapter ports.
- Added logic to query trunking info.

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