scsi: megaraid_sas: 32 bit descriptor fire cmd optimization

No functional change. Code refactor.

megasas_fire_cmd_fusion can always use 32 bit descriptor write for
ventura. No need to pass extra flag.  Only IOC INIT required 64 bit
Descriptor write.

Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>