Chrysler: add longitudinal control behind "Disable Radar" toggle

For Hyundai and Honda Bosch, we have [a hidden toggle](https://github.com/commaai/openpilot/blob/9eb27259c7b9bf267671b16d17ae9a21b43105f3/selfdrive/ui/qt/offroad/settings.cc#L81) that will allow you to enable long control; make the toggle visible by setting the `DisableRadar_Allow` param. The name doesn't really apply, but it's really the "radarless longitudinal" toggle.