rapidio: constify rio_device_id

rio_device_id are not supposed to change at runtime.  rio driver is
working with const 'id_table'.  So mark the non-const rio_device_id
structs as const.

Link: http://lkml.kernel.org/r/1503734627-6058-2-git-send-email-arvind.yadav.cs@gmail.com
Link: http://lkml.kernel.org/r/1503734627-6058-3-git-send-email-arvind.yadav.cs@gmail.com
Link: http://lkml.kernel.org/r/1503734627-6058-4-git-send-email-arvind.yadav.cs@gmail.com
Link: http://lkml.kernel.org/r/1503734627-6058-5-git-send-email-arvind.yadav.cs@gmail.com
Link: http://lkml.kernel.org/r/1503734627-6058-6-git-send-email-arvind.yadav.cs@gmail.com
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rapidio/switches/tsi568.c b/drivers/rapidio/switches/tsi568.c
index 8a43561..1214628b 100644
--- a/drivers/rapidio/switches/tsi568.c
+++ b/drivers/rapidio/switches/tsi568.c
@@ -169,7 +169,7 @@ static void tsi568_remove(struct rio_dev *rdev)
 	spin_unlock(&rdev->rswitch->lock);
 }
 
-static struct rio_device_id tsi568_id_table[] = {
+static const struct rio_device_id tsi568_id_table[] = {
 	{RIO_DEVICE(RIO_DID_TSI568, RIO_VID_TUNDRA)},
 	{ 0, }	/* terminate list */
 };