ACPI / video: Add enable_native_backlight quirk for MacbookPro12,1

It seems that the latest generation of MacbookPro needs to use the
native backlight driver, just like most modern laptops do, but it does
not automatically get enabled as the Apple BIOS does not advertise
Windows 8 compatibility. So add a quirk for this.

Reported-by: Christopher Beland <beland@alum.mit.edu>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>