[media] v4l2-ctrls.c: zero min/max/step/def values for 64 bit integers

Those fields are meaningless for such control types, and the control framework
should zero them. Otherwise v4l2-compliance will complain about non-zero
min/max/step/def fields.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>