[libata] pata_sch: notice attached slave devices

I posted this last month, but was prompted to do so again in bz#467457

Add capability flag to support slave devices with pata_sch driver.
Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/pata_sch.c

@@ -83,7 +83,7 @@ static struct ata_port_operations sch_pata_ops = {
 };
 
 static struct ata_port_info sch_port_info = {
-	.flags		= 0,
+	.flags		= ATA_FLAG_SLAVE_POSS,
 	.pio_mask	= ATA_PIO4,   /* pio0-4 */
 	.mwdma_mask	= ATA_MWDMA2, /* mwdma0-2 */
 	.udma_mask	= ATA_UDMA5,  /* udma0-5 */