licensing: add two missing spdx headers

Both files were developed in our tree, so they are under the default license.

hwdb.d/acpi-update.py

@@ -1,4 +1,5 @@
 #!/usr/bin/env python3
+# SPDX-License-Identifier: LGPL-2.1-or-later
 
 from html.parser import HTMLParser
 from enum import Enum

hwdb.d/ids_parser.py

@@ -1,4 +1,5 @@
 #!/usr/bin/env python3
+# SPDX-License-Identifier: LGPL-2.1-or-later
 
 import re
 import sys