[SCSI] bfa: Replace bfa_get_attr() with specific APIs

bfa_ioc_attr_s is a big structure and some times could cause
stack overflow if defined locally, so add specific APIs that
are needed to replace the use of ioc_attr local var.

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