move OAP messages implementations to libosmocore

This corresponds to change-id If5099e60681a215e798b6675f21813f26769c253 in
libosmocore, which is now required to build openbsc.

Related: OS#1592
Change-Id: I2f06aaa6eb54eafa860cfed8e72e41d82ff1c4cf
diff --git a/openbsc/tests/oap/Makefile.am b/openbsc/tests/oap/Makefile.am
index 06ccf33..bb9ebb2 100644
--- a/openbsc/tests/oap/Makefile.am
+++ b/openbsc/tests/oap/Makefile.am
@@ -28,7 +28,6 @@
 
 oap_test_LDADD = \
 	$(top_builddir)/src/gprs/oap.o \
-	$(top_builddir)/src/gprs/oap_messages.o \
 	$(top_builddir)/src/gprs/gprs_utils.o \
 	$(top_builddir)/src/libcommon/libcommon.a \
 	$(LIBOSMOCORE_LIBS) \
diff --git a/openbsc/tests/oap/oap_test.c b/openbsc/tests/oap/oap_test.c
index d200ed2..68542fd 100644
--- a/openbsc/tests/oap/oap_test.c
+++ b/openbsc/tests/oap/oap_test.c
@@ -19,11 +19,10 @@
  */
 
 #include <osmocom/core/application.h>
+#include <osmocom/gsm/oap.h>
 
 #include <openbsc/debug.h>
-
 #include <openbsc/oap.h>
-#include <openbsc/oap_messages.h>
 
 #include <stdio.h>
 #include <string.h>
diff --git a/openbsc/tests/sgsn/Makefile.am b/openbsc/tests/sgsn/Makefile.am
index c5d90f6..9e1a5a8 100644
--- a/openbsc/tests/sgsn/Makefile.am
+++ b/openbsc/tests/sgsn/Makefile.am
@@ -55,7 +55,6 @@
 	$(top_builddir)/src/gprs/gprs_subscriber.o \
 	$(top_builddir)/src/gprs/gprs_gb_parse.o \
 	$(top_builddir)/src/gprs/oap.o \
-	$(top_builddir)/src/gprs/oap_messages.o \
         $(top_builddir)/src/gprs/gprs_llc_xid.o \
 	$(top_builddir)/src/gprs/gprs_sndcp_xid.o \
         $(top_builddir)/src/gprs/slhc.o \