include GPU driver lock down info in installation instructions

[trclancy]

Just a suggestion, several updates to Jammy (Ubuntu 22.04) caused the i915 770 driver on Serpent Canyon to get updated and thus had to drop into safe mode and use the Jammy 22.04 driver update instructions. Might help to offer suggestions on how to lock-down the driver, for example "sudo apt-mark hold". To ensure driver remains on upgrade command ,