sbp2: slimmer interface to scsi_mod

- sbp2scsi_reset does not need to take host_lock
- sbp2scsi_reset, as our device reset handler, does not need to stand in as
  bus reset or host reset handler
- let scsi_mod use scsi_host_template.name instead of .info
  (sbp2 is not an emulation anway)

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jody McIntyre <scjody@modernduck.com>