[Gentoo] Control brightness after reboot

Because this command need to execute at root permission, so add script under /etc/local.d.

1. Add stript under /etc/local.d/
# vim /etc/local.d/brightness.start

#!/bin/bash
sudo echo 1250 > /sys/class/backlight/intel_backlight/brightness

2. change script permission
chmod +x /etc/local.d/brightness.start

Reference:

• Brightness is reset to Maximum on every Restart