[SCSI] bfa: Add support for max target ports discovery

- Changes to avoid discovering NPIV port as remote port by the other
  NPIV ports created on same physical port when all the NPIV ports are
  part of the same zone in a fabric.
- Provided mechanism to support maximum number of target ports for a
  given initiator port (physical port + NPIV ports) irrespective of the
  way in which the initiator and target ports are zoned in the fabric.
- Introduced module_parameter max_rport_logins to restrict number of
  remote ports discovery which includes target and initiator remote ports.

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