[media] dt3155v4l: remove deprecated current_norm

Since this driver provides a g_std op the current_norm field isn't used
anyway, so just drop it.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/staging/media/dt3155v4l/dt3155v4l.c

@@ -829,7 +829,6 @@ static struct video_device dt3155_vdev = {
 	.minor = -1,
 	.release = video_device_release,
 	.tvnorms = DT3155_CURRENT_NORM,
-	.current_norm = DT3155_CURRENT_NORM,
 };
 
 /* same as in drivers/base/dma-coherent.c */