[LICENSE] Add SPDX Identifier
diff --git a/verilog/gl/user_id_programming.v b/verilog/gl/user_id_programming.v
index 78dbd63..4cdbaf3 100644
--- a/verilog/gl/user_id_programming.v
+++ b/verilog/gl/user_id_programming.v
@@ -11,6 +11,7 @@
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
/* Generated by Yosys 0.9+3621 (git sha1 84e9fa7, gcc 8.3.1 -fPIC -Os) */