scsi: elx: efct: Data structures and defines for hw operations

Start the population of the efct target mode driver.  The driver is
contained in the drivers/scsi/elx/efct subdirectory.

Create the efct directory and start population of the driver by adding
SLI-4 configuration parameters, data structures for configuring SLI-4
queues, converting from OS to SLI-4 IO requests, and handling async events.

Link: https://lore.kernel.org/r/20210601235512.20104-18-jsmart2021@gmail.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Co-developed-by: Ram Vegesna <ram.vegesna@broadcom.com>
Signed-off-by: Ram Vegesna <ram.vegesna@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>