oap: add oap testsuite skeleton

Sponsored-by: On-Waves ehf
diff --git a/openbsc/configure.ac b/openbsc/configure.ac
index fc30b5e..8b7ce62 100644
--- a/openbsc/configure.ac
+++ b/openbsc/configure.ac
@@ -209,6 +209,7 @@
     tests/trau/Makefile
     tests/sgsn/Makefile
     tests/subscr/Makefile
+    tests/oap/Makefile
     doc/Makefile
     doc/examples/Makefile
     Makefile)