scsi: scsi_debug: Add ZBC module parameter

scsi: scsi_debug: Add ZBC module parameter

Add the zbc module parameter to take either:
    0: none         (probably a conventional disk)
    1: host-aware
    2: host-managed

These values are chosen to match 'enum blk_zoned_model' found in
include/linux/blkdev.h . Instead of "none", "no" or "0" can be given.
Instead of "host-aware", "aware or "1" can be given. Instead of
"host-managed", "managed" or "2" can be given.

Note: the zbc parameter can only be given at driver/module load time; it
cannot be changed via sysfs thereafter.

At this time there is no ZBC "host-aware" implementation so that string (or
the value '1') results in a modprobe error.

Link: https://lore.kernel.org/r/20200422104221.378203-4-damien.lemoal@wdc.com
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>