V4L/DVB (5980): tda8083: fix frequency and symbolrate info

The TDA8083 supports a symbol rate from 12..30 MSym/s.
The Grundig 29504-451 tuner uses the TDA8060 down-converter,
which has a frequency range from 920..2200MHz.
Thanks-to: Lars Buerding <lindvb@metatux.net>

Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>