media: i2c: imx219: Complete default format initialization

Complete the default format initialization in init_cfg() filling in
the fields for the colorspace configuration copied from
imx219_set_default_format().

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>