media: i2c: Correct format propagation for st-mipid02

Format propagation in the st-mipid02 driver is incorrect in that when
setting format for V4L2_SUBDEV_FORMAT_TRY on the source pad, the
_active_ rather than _try_ format from the sink pad is propagated.
This causes problems with format negotiation - update the function to
propagate the correct format.

Fixes: 642bb5e8 ("media: st-mipid02: MIPID02 CSI-2 to PARALLEL bridge driver")
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>