scsi: lpfc: SLI path split: Refactor FDISC paths

scsi: lpfc: SLI path split: Refactor FDISC paths

This patch refactors the FDISC paths to use SLI-4 as the primary interface:

 - Conversion away from using SLI-3 iocb structures to set/access fields in
   common routines. Use the new generic get/set routines that were added.
   This move changes code from indirect structure references to using local
   variables with the generic routines.

 - Refactor routines when setting non-generic fields, to have both SLI3 and
   SLI4 specific sections. This replaces the set-as-SLI3 then translate to
   SLI4 behavior of the past.

Link: https://lore.kernel.org/r/20220225022308.16486-10-jsmart2021@gmail.com
Co-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>