[SCSI] bfa: New interface to handle firmware upgrade scenario

Split bfa_fcs_init() into bfa_fcs_attach() and bfa_fcs_init().

Removed empty function definitions in FCS modules

Modified driver to call bfa_fcs_attach() and bfa_fcs_init() as needed.

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