scsi: lpfc: Convert SCSI path to use common I/O submission path

This patch converts the SCSI I/O path from the iocb-centric interfaces to
the common I/O submission path which supports native SLI-4 WQEs.

A wrapper routine is put in place to distinguish SLI-3 from SLI. If SLI-3,
the same iocb-centric paths are used, perhaps with refactored code that is
explicitly for SLI-3.  For SLI-4, any iocb-related formatting is replaced
by wqe-based formatting, although much of that is addressed by the common
wqe templates in the SLI-4 path.

Link: https://lore.kernel.org/r/20201115192646.12977-14-james.smart@broadcom.com
Co-developed-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>