google/auron: Fix omitted ACPI KB backlight for variants

Restores KB backlight functionality for auron variants
gandof, lulu, and samus.

TEST: boot Lulu and observe KB backlight functional

Change-Id: Iaa852f9327ff1690111db610b4cc5266cd7925b4
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/17960
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
6 files changed