scsi: scsi_transport_fc: Add a max_bsg_segments field to struct fc_function_template

scsi: scsi_transport_fc: Add a max_bsg_segments field to struct fc_function_template

ibmvfc only supports a single segment for BSG FC passthrough.  Instead of
having it set a queue limits after creating the BSG queues, add a field so
that the FC transport can set it before allocating the queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240409143748.980206-6-hch@lst.de
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>