ncr5380: Implement NCR5380_dma_xfer_len and remove LIMIT_TRANSFERSIZE macro

Follow the example of the atari_NCR5380.c core driver and adopt the
NCR5380_dma_xfer_len() hook. Implement NCR5380_dma_xfer_len() for dtc.c
and g_NCR5380.c to take care of the limitations of these cards. Keep the
default for drivers using PSEUDO_DMA.

Eliminate the unused macro LIMIT_TRANSFERSIZE.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/arm/oak.c b/drivers/scsi/arm/oak.c
index db337b9..d95a1d4 100644
--- a/drivers/scsi/arm/oak.c
+++ b/drivers/scsi/arm/oak.c
@@ -26,6 +26,8 @@
 #define NCR5380_write(reg, value) \
 	writeb(value, priv(instance)->base + ((reg) << 2))
 
+#define NCR5380_dma_xfer_len(instance, cmd, phase)	(cmd->transfersize)
+
 #define NCR5380_queue_command		oakscsi_queue_command
 #define NCR5380_info			oakscsi_info
 #define NCR5380_show_info		oakscsi_show_info