media: i2c: ov4689: Implement vflip/hflip controls

media: i2c: ov4689: Implement vflip/hflip controls

The OV4689 sensor supports horizontal and vertical flipping. Add
appropriate controls to the driver. Toggling both array flip and
digital flip bits allows to achieve flipping while maintaining output
Bayer order. Note that the default value of hflip control corresponds
to both bits set, as it was before this patch.

Signed-off-by: Mikhail Rudenko <mike.rudenko@gmail.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>