Inspired by commits ac6ea04b and 4560ca50 that enabled this feature
for lenovo/x60 and lenovo/t60 with i945 chipset.
Change-Id: Ia04f58b8c3769b5734708c6a338bb80c13c5aeba
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/3994
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@gmail.com>