productiontests:dualscreen-tests: Fix backlight path
The lable of the backlight node for the first display changed in devicetree. Adapt the sysfs path accordingly.
Dear all, On Thursday, 4th September 2025, we will test the new disaster recovery environment. A disaster recovery test will take place between 4:00 PM and 6:00 PM CEST. Please refrain from making any changes, as they will be lost. Once testing is complete, the production environment will be restored. Thank you for your understanding.
The lable of the backlight node for the first display changed in devicetree. Adapt the sysfs path accordingly.