media: imx: imx7-media-csi: Fix video field handling

media: imx: imx7-media-csi: Fix video field handling

Commit ef5ecd836017 ("media: imx: Try colorimetry at both sink and
source pads") reworked the way that formats are set on the sink pad of
the CSI subdevice, and accidentally removed video field handling.
Restore it by defaulting to V4L2_FIELD_NONE if the field value isn't
supported, with the only two supported value being V4L2_FIELD_NONE and
V4L2_FIELD_INTERLACED.

Fixes: ef5ecd836017 ("media: imx: Try colorimetry at both sink and source pads")
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>