Do not require 'Google Copyright' in coreboot headers

It should be possible to add non Google originated files to the
coreboot repo. Remove the check function, as coreboot was the last
repo using it.

BUG=none
TEST=with this change submitting coreboot files without Google
     copyright does not trigger presubmit warnings anymore.

Change-Id: I176f03a77202fbb216987822dd07204a213f7488
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/193506
Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Vadim Bendebury <vbendeb@google.com>
1 file changed