ia64, scsi: update references for the device-io book

The book is now at Documentation/driver-api/device-io.rst.
Update such references.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/drivers/scsi/qla1280.c b/drivers/scsi/qla1280.c
index 634254a..8a29fb0 100644
--- a/drivers/scsi/qla1280.c
+++ b/drivers/scsi/qla1280.c
@@ -3390,7 +3390,7 @@ qla1280_isp_cmd(struct scsi_qla_host *ha)
 	 *    On PCI bus, order reverses and write of 6 posts, then index 5,
 	 *       causing chip to issue full queue of stale commands
 	 * The mmiowb() prevents future writes from crossing the barrier.
-	 * See Documentation/DocBook/deviceiobook.tmpl for more information.
+	 * See Documentation/driver-api/device-io.rst for more information.
 	 */
 	WRT_REG_WORD(&reg->mailbox4, ha->req_ring_index);
 	mmiowb();