gfxinfo / machine_registration: More tag-stability-breaking changes

We have already made changes that would change the list of tags generated for a machine which means the DUTs will need to be go through training again... so let's use this opportunity to improve tags or add new ones.

What I like the most about this series is the fact that we should get gpu tags on device-tree-based platforms, and also that we will now know if we booted using efi or not and if resizeable bar is active or not \o/