tristate features will automatically disable if dependencies marked
as required are missing.
Packagers can manually override using `auto_features`.
Link: https://mesonbuild.com/Build-options.html#features
This plugin is only enabled when coreboot isn't detected.
It intentionally does not check for EFI to be disabled at startup
since it can also notify the user that UEFI capsule updates are
disabled on the system even if running in UEFI mode.
