treewide: Fix license headers to conform with linter

BRANCH=none
BUG=none
TEST=cros lint

Signed-off-by: Jakub Czapiga <jacz@semihalf.com>
Change-Id: I7710c43c8c70cf257a898f22c42ecbf350e125a2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3925702
Commit-Queue: Jakub Czapiga <czapiga@google.com>
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
Tested-by: Jakub Czapiga <czapiga@google.com>