scsi: firewire: sbp2: Declare the SCSI host template const

Make it explicit that the sbp2 host template it not modified.

Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230322195515.1267197-6-bvanassche@acm.org


Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>