[media] siano: always load smsdvb

Without smsdvb, the driver actually does nothing, as it
lacks the userspace API.
While I wrote it independently, in order to make a sms2270 board
I have here to work, this patch is functionally identical to this
patch from Doron Cohen:
	http://patchwork.linuxtv.org/patch/7894/

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>