V4L/DVB (8567): gspca: hflip and vflip controls added for ov519 - ov7670 plus init cleanup.

The hflip and vflip controls work for ov7670 only.
This bridge/sensor inverts blue and red - not fixed.

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>