Resolution: don't display disabled resolutions

[CarterLi]

Before:

After:

This issue affects both tty and wayland.

Note this method reports preferred / maximum resolution instead of current resolution as I said before. I highly recommand https://github.com/dylanaraps/neofetch/pull/2395 if you use wayland

[CarterLi]

AD: fastfetch uses libdrm to fetch current resolution and refresh rate, which is not available in /sys/class/drm