scsi: lpfc: Rework lpfc to allow different sli4 cq and eq handlers

Up until now, an SLI-4 device had no variance in the way it handled
its EQs and CQs. With newer hardware, there are now differences in
doorbells and some differences in how entries are valid.

Prepare the code for new hardware by creating a sli4-based callout
table that can be set based on if_type.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>