V4L/DVB: Add support for SMT7020 to cx88

This patch adds support for the built-in dvb device
of a Samsung SMT7020s (x86 based STB) to the cx88 family.

Signed-off-by: Dirk Herrendoerfer <d.herrendoerfer@herrendoerfer.name>
Signed-off-by: Helmut Auer <helmut@helmutauer.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>