The Acer Aspire 3830TG predates Windows 8, so it defaults to using
acpi_video# for backlight control, but this is non functional on
this model.

Add a DMI quirk to use the native backlight interface which does
work properly.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>