Add in a few missing -2023 dates in copyright notice

Change-Id: Iba9367ba8e4cd395789d58b7ded52e74459af6c8
diff --git a/makefiles/targets/check.mk b/makefiles/targets/check.mk
index 2145343..aa1b0d0 100644
--- a/makefiles/targets/check.mk
+++ b/makefiles/targets/check.mk
@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-# SPDX-FileCopyrightText: 2022 Open Networking Foundation (ONF) and the ONF Contributors
+# SPDX-FileCopyrightText: 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
 # SPDX-License-Identifier: Apache-2.0
 # -----------------------------------------------------------------------
 
diff --git a/makefiles/targets/clean.mk b/makefiles/targets/clean.mk
index f504dec..f787e5c 100644
--- a/makefiles/targets/clean.mk
+++ b/makefiles/targets/clean.mk
@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-# SPDX-FileCopyrightText: 2022 Open Networking Foundation (ONF) and the ONF Contributors
+# SPDX-FileCopyrightText: 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
 # SPDX-License-Identifier: Apache-2.0
 # -----------------------------------------------------------------------
 
diff --git a/makefiles/targets/sterile.mk b/makefiles/targets/sterile.mk
index 1eb7035..c661f53 100644
--- a/makefiles/targets/sterile.mk
+++ b/makefiles/targets/sterile.mk
@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-# SPDX-FileCopyrightText: 2022 Open Networking Foundation (ONF) and the ONF Contributors
+# SPDX-FileCopyrightText: 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
 # SPDX-License-Identifier: Apache-2.0
 # -----------------------------------------------------------------------
 
diff --git a/makefiles/targets/test.mk b/makefiles/targets/test.mk
index d70fa4a..2f68086 100644
--- a/makefiles/targets/test.mk
+++ b/makefiles/targets/test.mk
@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-# SPDX-FileCopyrightText: 2022 Open Networking Foundation (ONF) and the ONF Contributors
+# SPDX-FileCopyrightText: 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
 # SPDX-License-Identifier: Apache-2.0
 # -----------------------------------------------------------------------
 
diff --git a/makefiles/targets/tox.mk b/makefiles/targets/tox.mk
index b3a638b..44da921 100644
--- a/makefiles/targets/tox.mk
+++ b/makefiles/targets/tox.mk
@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-# SPDX-FileCopyrightText: 2022 Open Networking Foundation (ONF) and the ONF Contributors
+# SPDX-FileCopyrightText: 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
 # SPDX-License-Identifier: Apache-2.0
 # -----------------------------------------------------------------------