util/lint & LICENSES: Add GCC-exception-3.1 to license exceptions

The gcov files in the lib directory are licensed GPL 3.0 with the GCC
runtime library exception.

Add this as a valid license so that the files can get a correct SPDX
identifier.

Signed-off-by: Martin Roth <martin.roth@amd.corp-partner.google.com>
Change-Id: I1cf9c3125592741923c9b4481038055f24fe6ab1
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66495
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>

LICENSES/exceptions/GCC-exception-3.1.txt

@@ -0,0 +1,74 @@
+GCC RUNTIME LIBRARY EXCEPTION
+
+Version 3.1, 31 March 2009
+
+General information: http://www.gnu.org/licenses/gcc-exception.html
+
+Copyright (C) 2009 Free Software Foundation, Inc. <http://fsf.org/>
+
+Everyone is permitted to copy and distribute verbatim copies of this
+license document, but changing it is not allowed.
+
+This GCC Runtime Library Exception ("Exception") is an additional
+permission under section 7 of the GNU General Public License, version 3
+("GPLv3"). It applies to a given file (the "Runtime Library") that bears
+a notice placed by the copyright holder of the file stating that the
+file is governed by GPLv3 along with this Exception.
+
+When you use GCC to compile a program, GCC may combine portions of
+certain GCC header files and runtime libraries with the compiled
+program. The purpose of this Exception is to allow compilation of
+non-GPL (including proprietary) programs to use, in this way, the header
+files and runtime libraries covered by this Exception.
+
+0. Definitions.
+
+  A file is an "Independent Module" if it either requires the Runtime
+  Library for execution after a Compilation Process, or makes use of an
+  interface provided by the Runtime Library, but is not otherwise based
+  on the Runtime Library.
+
+  "GCC" means a version of the GNU Compiler Collection, with or without
+  modifications, governed by version 3 (or a specified later version) of
+  the GNU General Public License (GPL) with the option of using any
+  subsequent versions published by the FSF.
+
+  "GPL-compatible Software" is software whose conditions of propagation,
+  modification and use would permit combination with GCC in accord with
+  the license of GCC.
+
+  "Target Code" refers to output from any compiler for a real or virtual
+  target processor architecture, in executable form or suitable for
+  input to an assembler, loader, linker and/or execution phase.
+  Notwithstanding that, Target Code does not include data in any format
+  that is used as a compiler intermediate representation, or used for
+  producing a compiler intermediate representation.
+
+  The "Compilation Process" transforms code entirely represented in
+  non-intermediate languages designed for human-written code, and/or in
+  Java Virtual Machine byte code, into Target Code. Thus, for example,
+  use of source code generators and preprocessors need not be considered
+  part of the Compilation Process, since the Compilation Process can be
+  understood as starting with the output of the generators or
+  preprocessors.
+
+  A Compilation Process is "Eligible" if it is done using GCC, alone or
+  with other GPL-compatible software, or if it is done without using any
+  work based on GCC. For example, using non-GPL-compatible Software to
+  optimize any GCC intermediate representations would not qualify as an
+  Eligible Compilation Process.
+
+1. Grant of Additional Permission.
+
+   You have permission to propagate a work of Target Code formed by
+   combining the Runtime Library with Independent Modules, even if such
+   propagation would otherwise violate the terms of GPLv3, provided that
+   all Target Code was generated by Eligible Compilation Processes. You
+   may then convey such a combination under terms of your choice,
+   consistent with the licensing of the Independent Modules.
+
+2. No Weakening of GCC Copyleft.
+
+  The availability of this Exception does not imply any general
+  presumption that third-party software is unaffected by the copyleft
+  requirements of the license of GCC.

util/lint/lint-000-license-headers

@@ -101,6 +101,7 @@ check_for_license 'SPDX-License-Identifier: GPL-2.0-only'
 check_for_license 'SPDX-License-Identifier: GPL-2.0-or-later'
 check_for_license 'SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note'
 check_for_license 'SPDX-License-Identifier: GPL-3.0-only'
+check_for_license 'SPDX-License-Identifier: GPL-3.0-only WITH GCC-exception-3.1'
 check_for_license 'SPDX-License-Identifier: GPL-3.0-or-later'
 check_for_license 'SPDX-License-Identifier: HPND'
 check_for_license 'SPDX-License-Identifier: HPND-sell-variant'