V4L/DVB (12942): SAA7164: HVR2250 changes related to attach time tuner configuration

Ensure that by default all tuners are set correctly to master/slave mode.
For all HVR2250's, ensure slave based tuners are caliberated during attach
to avoid locking problems on tuner# above channel 91.

HVR2200 tuner attach time to be reviewed in a future patch.

Signed-off-by: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>