[media] em28xx: ERROR: "em28xx_add_into_devlist" [drivers/media/video/em28xx/em28xx.ko] undefined!

Signed-off-by: Chris Rankin <rankincj@yahoo.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>