v4l2object: add support for vertical padding when importing buffers
v4l2object: add support for vertical padding when importing buffers

We were already supporting horizontal padding by setting bytesperline to
the buffer stride but not vertical one.

We are now updating the format height with the padded height and crop to
the actual video resolution if needed.

pexip/gst-plugins-good,GStreamer/gst-plugins-good,pexip/gst-plugins-good,pexip/gst-plugins-good,GStreamer/gst-plugins-good,pexip/gst-plugins-good,GStreamer/gst-plugins-good,pexip/gst-plugins-good,GStreamer/gst-plugins-good