V4L/DVB (11386): saa7134: Add analog RF tuner support for Avermedia A700 DVB-S Hybrid+FM card

Thanks to panagonov <panagonov@mail.bg> for requesting support and
testing patches.

Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>