759d706f7c
Tegra194 contains a fourth display controller that does not own any windows. Therefore, we cannot currently assign a primary plane to it which causes KMS to eventually crash. Do not register the display controller if it owns no windows to work around this. Note that we still have to enable and probe the display controller because for some reason all display controllers need to be powered (and/or clocked) before any registers can be accessed in any of the display controllers. Signed-off-by: Thierry Reding <treding@nvidia.com>