media: atomisp: remove left-over videobuf include

This source still included the media/videobuf-vmalloc.h
header, even though it is no longer used.

Since the old videobuf framework is about to be removed,
delete this include first.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>