Revert "[media] v4l2-dv-timings: fix a sparse warning"

Sparse got a fix for that. Also, it is suspected that reverting
this patch might cause compilation breakages on userspace. So,
revert it.

This reverts commit 5c2cacc1.

Requested-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>