Use a sink in the middle of the stream to correct for v4l2 timestamps with
hardware timestamps to monotonic clock.
This sink, together with other utilities related to data streaming, lives in a
new vive_source entity, with similar functionality to wmr_source or rs_source.
The vive_source lifetime is managed by the builder xfctx, which prevents
deallocation dependencies between vive_device and the v4l2_fs to cause segfaults.
Create propper initializer for the controller and move the proper
interface to vive_prober to be more consistent with the device. This
will also allow to share more code like the config parsing in a later
patch.
This adds a driver for the Vive family of devices based on Philipp
Zabel's ouvrt.
The driver currently only handles the IMU and main board report streams,
but is able to acquire the JSON configuration and utilize it for IMU
calibration as well as distortion configuration.
