BCM2835-V4L2: Correctly denote key frames in encoded data

Forward MMAL key frame flags to the V4L2 buffers.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c

@@ -398,6 +398,9 @@ static void buffer_cb(struct vchiq_mmal_instance *instance,
  dev->capture.last_timestamp = buf->vb.vb2_buf.timestamp;
 
  vb2_set_plane_payload(&buf->vb.vb2_buf, 0, length);
+ if (mmal_flags & MMAL_BUFFER_HEADER_FLAG_KEYFRAME)
+ buf->vb.flags |= V4L2_BUF_FLAG_KEYFRAME;
+
  v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
  "Buffer has ts %llu",
  dev->capture.last_timestamp);