V4L/DVB (3196): correct Thomson DTT 761x frequency ranges

- Corrected Thomson DTT 7611 tuner programming, based on spec sheet
- renamed to Thomson DTT 761x
- applies to DTT 7611 7611A 7612 7613 7613A 7614 7615 7615A
(DTT 7610 is similar, but slightly different programming)
- corrected frequency ranges for analog and digital modes

Signed-off-by: Michael Krufky <mkrufky@m1k.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>