It seems Orin does not use pinctrl-tegra186-dpaux.c driver for DisplayPort Auxiliary.
Could you refer to the following threads for this use case?
How can I remove text printing from the UEFI Logo interface? - #4 by KevinFFF
Close or hide UEFI menu - #3 by KevinFFF
You can just comment out DisplaySystemAndHotkeyInformation() function to prevent it printed.