[SCSI] bfa: Driver and BSG enhancements.

- Added a new module parameter max_xfer_size to
  set the max_sectors in the scsi_host template.
- Added logic to handle request_irq() failure so
  that msix vector resource is de-allocated immediately
  when failure happens.
- BSG enhancements to collect vHBA releated info and port log.
- Removed the workaround of incrementing the module refcnt on bsg request.

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