message: add vel argument to constant speed spoolup
diff: @@ -191,7 +191,7 @@ bool Axis::run_lockin_spin() {
  distance += vel * current_meas_period;
  phase = wrap_pm_pi(phase + vel * current_meas_period);
  - if (!motor_.update(config_.lockin_current, phase))
  + if (!motor_.update(config_.lockin_current, phase, vel))
  return false;
  return !spin_done();
  });
  