Display Port minitest

This minitest is a good test for the Gigabit Transcievers (GTP tiles) documentation process.

The test uses the Hamsternz's Display Port as a third party project.

To run the whole flow to generate the final FASM file run:

make all

To run the same flow, but with Yosys synthesis, run:

make all SYNTH=yosys

All the pre-requisites (LiteX, Yosys, etc.) are automatically installed/built. It is required though to have Vivado installed in the system.