Hello Holger Kupka,
You can find the BDSL for the i.MX6DP on the Tools & Software section of the i.MX6DP page:
The direct link to the file is below:
https://www.nxp.com/webapp/Download?colCode=IMX6DP-6QP-BSDL&appType=license
Inside you will see the BSDL files for the i.MX6DP and i.MX6QP.
I hope this helps!
Regards,