Add missing licences

Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
diff --git a/tests/psa-client-server/psasim/src/psa_sim_crypto_server.c b/tests/psa-client-server/psasim/src/psa_sim_crypto_server.c
index 7e874d1..919eb84 100644
--- a/tests/psa-client-server/psasim/src/psa_sim_crypto_server.c
+++ b/tests/psa-client-server/psasim/src/psa_sim_crypto_server.c
@@ -2,6 +2,11 @@
 
 /* server implementations */
 
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+
 #include <stdio.h>
 #include <stdlib.h>
 
diff --git a/tests/psa-client-server/psasim/src/psa_sim_generate.pl b/tests/psa-client-server/psasim/src/psa_sim_generate.pl
index 7fea72c..19c6a0b 100755
--- a/tests/psa-client-server/psasim/src/psa_sim_generate.pl
+++ b/tests/psa-client-server/psasim/src/psa_sim_generate.pl
@@ -5,6 +5,9 @@
 # manually and the output files are what are to be reviewed. In due course
 # this will be replaced by a Python script.
 #
+# Copyright The Mbed TLS Contributors
+# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+#
 use strict;
 use Data::Dumper;
 use JSON qw(encode_json);
@@ -251,6 +254,11 @@
 
 /* server implementations */
 
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+
 #include <stdio.h>
 #include <stdlib.h>
 
diff --git a/tests/psa-client-server/psasim/src/psa_sim_serialise.pl b/tests/psa-client-server/psasim/src/psa_sim_serialise.pl
index b89d058..5161db1 100755
--- a/tests/psa-client-server/psasim/src/psa_sim_serialise.pl
+++ b/tests/psa-client-server/psasim/src/psa_sim_serialise.pl
@@ -10,6 +10,9 @@
 # perl psa_sim_serialise.pl h > psa_sim_serialise.h
 # perl psa_sim_serialise.pl c > psa_sim_serialise.c
 #
+# Copyright The Mbed TLS Contributors
+# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+#
 use strict;
 
 my $usage = "$0: usage: $0 c|h\n";