scsi: remove the use_clustering flag

The same effects can be achieved by setting the dma_boundary to
PAGE_SIZE - 1 and the max_segment_size to PAGE_SIZE, so shift those
settings into the drivers.  Note that in many cases the setting might
be bogus, but this keeps the status quo.

[mkp: fix myrs and myrb]

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

drivers/scsi/a2091.c

@@ -160,7 +160,7 @@ static struct scsi_host_template a2091_scsi_template = {
 	.this_id		= 7,
 	.sg_tablesize		= SG_ALL,
 	.cmd_per_lun		= CMD_PER_LUN,
-	.use_clustering		= DISABLE_CLUSTERING
+	.dma_boundary		= PAGE_SIZE - 1,
 };
 
 static int a2091_probe(struct zorro_dev *z, const struct zorro_device_id *ent)