[SCSI] bfa: add PBC port disable handling

Add PBC port disable handling in BFA and return the appropriate status from
BFA APIs. In bfa_fcs_lport.c, handle OFFLINE event to avoid BFA_ASSERT.

Signed-off-by: Jing Huang <huangj@brocade.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>