V4L/DVB: pvrusb2: Fix Gotview hardware support

pvrusb2: Fix RF tuner problem with gotview hardware - this bug was
introduced when switching over to the subdev model of driver control

Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>