Add extra line about src files are part of RIC platform project

Signed-off-by: Timo Tietavainen <timo.tietavainen@nokia.com>
Change-Id: Idf0de8c3b3c8133847f14d0d0b1b38a68fcb2c67
diff --git a/tst/wellknownerrorcode.cpp b/tst/wellknownerrorcode.cpp
index 5d6fec5..3b0b16c 100644
--- a/tst/wellknownerrorcode.cpp
+++ b/tst/wellknownerrorcode.cpp
@@ -14,6 +14,11 @@
    limitations under the License.
 */
 
+/*
+ * This source code is part of the near-RT RIC (RAN Intelligent Controller)
+ * platform project (RICP).
+*/
+
 #include "private/tst/wellknownerrorcode.hpp"
 #include <cerrno>