[GPRS] hand SNDCP N-PDUs to the GTP to the GGSN

This so far only works for UNIT-DATA and only if the N-PDU is not fragmented at
the SNDCP layer.
diff --git a/openbsc/src/gprs/Makefile.am b/openbsc/src/gprs/Makefile.am
index 11b2ac9..30b45f6 100644
--- a/openbsc/src/gprs/Makefile.am
+++ b/openbsc/src/gprs/Makefile.am
@@ -19,7 +19,7 @@
 			$(top_srcdir)/src/socket.c $(top_srcdir)/src/debug.c
 osmo_gbproxy_LDADD = libgb.a $(top_builddir)/src/libvty.a
 
-osmo_sgsn_SOURCES =	gprs_gmm.c gprs_sgsn.c \
+osmo_sgsn_SOURCES =	gprs_gmm.c gprs_sgsn.c gprs_sndcp.c \
 			sgsn_main.c sgsn_vty.c sgsn_libgtp.c \
 			$(top_srcdir)/src/socket.c $(top_srcdir)/src/debug.c
 osmo_sgsn_LDADD = libgb.a $(top_builddir)/src/libvty.a -lgtp