Build fixes

Some fixes for build environments where dependencies are installed in
distinct directories.

Change-Id: I38808fd2911747b266ee6fde91187a88dd7ae355
diff --git a/openbsc/tests/mm_auth/Makefile.am b/openbsc/tests/mm_auth/Makefile.am
index 7eb14fa..cb35198 100644
--- a/openbsc/tests/mm_auth/Makefile.am
+++ b/openbsc/tests/mm_auth/Makefile.am
@@ -6,6 +6,7 @@
 AM_CFLAGS = \
 	-Wall \
 	$(LIBOSMOCORE_CFLAGS) \
+	$(LIBOSMOABIS_CFLAGS) \
 	$(LIBOSMOGSM_CFLAGS) \
 	$(LIBCRYPTO_CFLAGS) \
 	$(NULL)