[media] v4l2-subdev: support new 'which' field in enum_mbus_code

Support the new 'which' field in the enum_mbus_code ops. Most drivers do not
need to be changed since they always return the same enumeration regardless
of the 'which' field.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/platform/am437x/am437x-vpfe.c

@@ -2327,6 +2327,7 @@ vpfe_async_bound(struct v4l2_async_notifier *notifier,
 
 		memset(&mbus_code, 0, sizeof(mbus_code));
 		mbus_code.index = j;
+		mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 		ret = v4l2_subdev_call(subdev, pad, enum_mbus_code,
 			       NULL, &mbus_code);
 		if (ret)