V4L/DVB: Update for MT2060 to use dvb_tuner_ops

new tuner api
minor fixes for tuning

Signed-off-by: Olivier DANET <odanet@caramail.com>
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>