V4L/DVB (12092): gspca_sonixj + ov7630: invert vflip control instead of changing default

gspca_sonixj + ov7630 had the default value for flip enabled, as otherwise
the picture is upside down. It is better to instead invert the meaning
of the control in the set function, and have the default be no vflip,
as one would expect vflip enabled to be upside down.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>