media: admin-guide: bt8xx.rst: fix a broken cross-reference

The old cards.rst file doesn't exist anymore. Also, it is not
the right reference there, as it should be pointing to the
bttv-specific cardlist.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Mauro Carvalho Chehab 2020-04-18 11:59:20 +02:00
commit f45ce7a1e5