[media] v4l: fix handling of v4l2_input.capabilities

The v4l core sets the v4l2_input.capabilities field based on the supplied
v4l2_ioctl_ops. However, several drivers do a memset or memcpy of the v4l2_input
struct, thus overwriting that field incorrectly.

Either remove the memset (which is already done by the v4l core), or add the
proper capabilities field in case of a memcpy.

The same is also true for v4l2_output, but that only affected the ivtv driver.

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