Brightness control should support multiple screens
Feature summary
Some newer laptops have multiple screens and we need to be able to control the backlight of each of them.
How would you like it to work
Either one backlight control per screen or one for all. Keyboard backlight control should trigger all devices.
Relevant links, screenshots, screencasts etc.
Issue about it on a repository about a laptop that has two screens: https://github.com/s-light/ASUS-ZenBook-Pro-Duo-UX581GV/issues/1#issuecomment-633702178
Example device (Asus UX481FA) with two screens and with correct driver, two backlight devices:
Edited by moshemalawach