V4L/DVB: ngene: Set ADC ranges to 1Vpp

Set ADC1 and ADC2 range of the stv0900 to 1Vpp.

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