scsi: dtc: remove from tree

The driver has not seen any maintainer activity or other work that
wasn't tree wide conversion or clenaups in the entire history of
the git tree.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Acked-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>