Obtain two V4L2Devices and use one to obtain a BufferPool.
Propagate the formats from the first to the second device and then commence
sending buffers between the two devices in a ping-pong fashion.
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
