[SCSI] lpfc 8.3.28: Add Loopback support for SLI4 adapters

- Add Basic support for SLI4 Loopback.
  (CR 124951, 125766, 124951, 125843, 125832, 125843)
- Added missing protection in setting/clearing of phba->link_flag bit
  field (CR 125994)
- Use link type and link number obtained from READ_CONFIG mailbox
  command. (CR 126264)

Signed-off-by: Alex Iannicelli <alex.iannicelli@emulex.com>
Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>