also remove the elogind specific patch to use systemd for brightness
changes

Co-authored-by: Clayton Craft <clayton@craftyguy.net>

Note: the user services that the -systemd split pkg installs are not
enabled by default using systemd presets. None of them have 'Install'
sections, they appear to be mostly/all dbus activated instead.

[ci:ignore-count]
[ci:skip-build]: already built successfully in CI