scsi: mpi3mr: Add shost related sysfs attributes

Add shost related sysfs attributes to display the controller's firmware
version, queue depth, number of requests, and number of reply queues. Also
add an attribute to set & get the logging_level.

Link: https://lore.kernel.org/r/20220517115310.13062-2-sreekanth.reddy@broadcom.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>