media: ddbridge: evaluate the actual link when setting up the dummy tuner

Devices supporting dummy tuner operation can exist on any link, not only
on link 0, so fix this accordingly.

Picked up from the upstream dddvb GIT.

Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>