[SCSI] bfa: FC credit recovery and misc bug fixes.

- Introduce FC credit recovery.
- Added module parameter to enable/disable credit recovery.

Bug Fixes:
- Removed check for ignoring plogi from initiator in switched fabric mode.
- The ABTS for PLOGI is going out few millisecs earlier due to FW
  timer calibration (around 300 miilisecs earlier). So there is a
  window if an accept comes during this time HBA would have initiated
  an ABORT.
- Added 1 to FC_ELS_TOV for compensating for FW timer.

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