scsi: smartpqi: remove the smp_handler stub

The SAS transport class will do the right thing and not register the BSG
node if now smp_handler method is present.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>