Sunsetting PowerDevil's XRandrBrightness

[Oded Arbel]

On Kubuntu 20.04 with Plasma 5.18, I'm not use xrandr:

powerdevil: Backend loaded, loading core
powerdevil: Core loaded, initializing backend
powerdevil: Xrandr not supported, trying ddc, helper
powerdevil: [DDCutilBrightness] compiled without DDC/CI support
powerdevil: Falling back to helper to get brightness

It looks like it is using
/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight

The device is a laptop with Optimus and using Intel HD 630 for the display.
--
Oded