media: staging/imx: fill vb2_v4l2_buffer field entry

- fixes gstreamer v4l2src warning:

  0:00:00.716640334  349  0x164f720 WARN  v4l2bufferpool gstv4l2bufferpool.c:1195:gst_v4l2_buffer_pool_dqbuf:<v4l2src0:pool:src> Driver should never set v4l2_buffer.field to ANY

- fixes v4l2-compliance test failure:

  Streaming ioctls:
          test read/write: OK (Not Supported)
              Video Capture:
                  Buffer: 0 Sequence: 0 Field: Any Timestamp: 58.383658s
                  fail: v4l2-test-buffers.cpp(297): g_field() == V4L2_FIELD_ANY

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Reviewed-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/staging/media/imx/imx-ic-prpencvf.c

@@ -210,6 +210,7 @@ static void prp_vb2_buf_done(struct prp_priv *priv, struct ipuv3_channel *ch)
 
 	done = priv->active_vb2_buf[priv->ipu_buf_num];
 	if (done) {
+		done->vbuf.field = vdev->fmt.fmt.pix.field;
 		vb = &done->vbuf.vb2_buf;
 		vb->timestamp = ktime_get_ns();
 		vb2_buffer_done(vb, priv->nfb4eof ?

drivers/staging/media/imx/imx-media-csi.c

@@ -236,6 +236,7 @@ static void csi_vb2_buf_done(struct csi_priv *priv)
 
 	done = priv->active_vb2_buf[priv->ipu_buf_num];
 	if (done) {
+		done->vbuf.field = vdev->fmt.fmt.pix.field;
 		vb = &done->vbuf.vb2_buf;
 		vb->timestamp = ktime_get_ns();
 		vb2_buffer_done(vb, priv->nfb4eof ?