Improve the Linux 6.8+ compat patch, fix building on 6.10+

This patchset does two things: first, it removes the old deprecated class mechanism when building on 6.8+ ENTIRELY, unlike previous patch (7f851f5f) which simply replaced it with another class, that got removed in 6.10. Without I2C_CLASS_DDC auto-probing isn't working anyway, so just remove it entirely to at least allow building and not worry about other class removals in the future. While we're at it, print a warning in the dmesg so users can more easily figure out what's wrong.

This isn't ideal, as it will require users to configure the module manually, but as far as I can tell there isn't a way to do auto-probing as of now (it's possible that the DRM allows that somehow, it seems like the DDC interfaces are exposed in DRM bridges, however I'm terrified of DRM as a whole so I'm not going to look that up further, sorry).

The second patch fixes compatibility on 6.10.

Both of these patches should allow building on all kernel versions up to 6.10 (as the changes for 6.8+/6.10+ are guarded by LINUX_VERSION_CODE conditionals), however I've only tried it on 6.10.1 in NixOS.

Closes #44 (closed)