intel/cougar_canyon2: fix build

The reintroduction of cougar_canyon2 crossed beams with the
moving the GMA display brightness data in ACPI into individual
mainboards.

Make things build again by having the board use the same default values
that it used to use automatically. They may be wrong, but no worse than
what was there before.

Change-Id: Id788034c38b42e1c35d9cd17e9bbb2ce49e3e91c
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/12132
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/mainboard/intel/cougar_canyon2/dsdt.asl

@@ -45,6 +45,7 @@ DefinitionBlock(
 		{
 			#include <northbridge/intel/fsp_sandybridge/acpi/sandybridge.asl>
 			#include <southbridge/intel/fsp_bd82x6x/acpi/pch.asl>
+			#include <drivers/intel/gma/acpi/default_brightness_levels.asl>
 		}
 	}