[LICENSE] Add SPDX Identifier
diff --git a/utils/addmpwseal.tcl b/utils/addmpwseal.tcl
index 4320fe2..7473760 100644
--- a/utils/addmpwseal.tcl
+++ b/utils/addmpwseal.tcl
@@ -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
 
 drc off
 gds readonly true