Missing support for old AMD cards

[totchi-lagawi]

The README claims support for macOS down to macOS High Sierra. Despite being the latest one to do so, this version supports AMD HD 2000 to AMD HD 6000 GPU series, however OpCore-Simplify says it is unsupported.

I think it would be better to actually tell the user this graphics card is not supported by OpCore-Simplify, but is actually supported by macOS (up to High Sierra). Obviously, proper support would be better, but, well, no one's got infinite time...

Anyway thanks for the tool!

[lzhoang2801]

Help me create a pull request for this. Thanks

[totchi-lagawi]

Will do, as soon as I get macOS running on that computer.