[media] Remove the old V4L1 v4lgrab.c file

This example file uses the old V4L1 API. It also doesn't use libv4l.
So, it is completely obsolete. A good example already exists at
v4l-utils (v4l2grab.c):
	http://git.linuxtv.org/v4l-utils.git

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