Recent versions of gnu-efi are distributed under the term of the BSD License (mix of 2-clause and 3-clause ones AFAIK but I didn't check carefully whether "BSD BSD-2" is accurate or not, though) instead of GPLv2.
BSD, BSD-2, GPL-2+ (for grub files) looks correct. Pushed as: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=f95a6825dd3d61775cd6bb5cff62c21701037a16 Thank you!