samsung-laptop: Add quirk for broken acpi_video backlight on N250P

BugLink: http://bugs.launchpad.net/bugs/1086921


Cc: stable@vger.kernel.org # v3.4+
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>