[media] tlg2300: use correct device parent

Set the correct parent for v4l2_device_register and don't set the name
anymore (that's now deduced from the parent). Also remove an unnecessary
forward reference and fix two weird looking log messages.

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