Now that libcamera creates threads internally and doesn't rely on an application-provided event loop, remove the thread from the V4L2 compatibility layer. The split between the V4L2CameraProxy and V4L2Camera classes is still kept to separate the V4L2 adaptation from camera operation. This may be further refactored later. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>