To work around this issue you can use the High Speed SelectIO to set up everything else that is required for your interface and generate the output products.
Then replace the .XCI file with the <<component name>>.v and other required files.
The LOC and IOSTANDARD constraints will also need to be added.
They can be found in the <<component name>>.xdc file.
Note: the port names may need to be changed.
Once the files have been replaced you can edit the files to change the 3-state connections.
Please refer to (Xilinx Answer 64216) High Speed SelectIO - Known Issue List for software version that the issue is resolved in.