Currently there is no LVDS on the Apalis T30. In the Release Roadmap this issue is listed and there should be a workarround to get it working.
Can someone explain how i can implement this workarround?
You are right, that this issue is related to the roadmap issue 7250. As long as this is not fixed in the image itself we propose the following workaround:
You can configure the pins as required by your setup using the GPIO lib. Therefore you can use this sample code. The GPIO lib you get from here. Adjust the code as you need it and put the finished application into \FlashDisk\Autorun, so the small application get executed after the system has booted and configures the screen according to your needs.