commit 129ff8f8 upstream.

Or else the laptop will boot with a dimmed screen.

References: https://bugzilla.kernel.org/show_bug.cgi?id=51141


Tested-by: Stefan Nagy <public@stefan-nagy.at>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>