The Dell Precision 7510 has a broken acpi-video implementation.

The backlight control bits work, but when the brightness is changed via
the acpi-video interface the backlight flickers annoyingly before settling
at the new brightness, switching to using the native interface fixes the
flickering so add a quirk for this (the vendor interface can not change the
brightness at all).
Signed-off-by: Shih-Yuan Lee (FourDollars) <sylee@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>