sbp2: Merge TYPE_RBC and 10byte removal patch from scsi maintainers.

Added more cleanups to remove unused code.

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