Build fixes

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

Change-Id: I38808fd2911747b266ee6fde91187a88dd7ae355
diff --git a/openbsc/src/gprs/Makefile.am b/openbsc/src/gprs/Makefile.am
index 02c8878..59136bd 100644
--- a/openbsc/src/gprs/Makefile.am
+++ b/openbsc/src/gprs/Makefile.am
@@ -28,10 +28,12 @@
 
 OSMO_LIBS = \
 	$(LIBOSMOCORE_LIBS) \
+	$(LIBOSMOABIS_LIBS) \
 	$(LIBOSMOGSM_LIBS) \
 	$(LIBOSMOVTY_LIBS) \
 	$(LIBOSMOCTRL_LIBS) \
 	$(LIBOSMOGB_LIBS) \
+	$(LIBGTP_LIBS) \
 	$(NULL)
 
 bin_PROGRAMS = \
@@ -121,6 +123,6 @@
 	$(LIBOSMOGSM_LIBS) \
 	$(LIBOSMOVTY_LIBS) \
 	$(LIBCARES_LIBS) \
+	$(LIBGTP_LIBS) \
 	-lrt \
-	-lgtp \
 	$(NULL)