gprs_ns2: add gprs_ns2_ip_vc_local() return the local sockaddr

Change-Id: I65a739772596015b90473045d32d4934d924e43f
diff --git a/include/osmocom/gprs/gprs_ns2.h b/include/osmocom/gprs/gprs_ns2.h
index 5f341d9..d332e48 100644
--- a/include/osmocom/gprs/gprs_ns2.h
+++ b/include/osmocom/gprs/gprs_ns2.h
@@ -140,6 +140,7 @@
 			    uint16_t nsei);
 
 const struct osmo_sockaddr *gprs_ns2_ip_vc_remote(struct gprs_ns2_vc *nsvc);
+const struct osmo_sockaddr *gprs_ns2_ip_vc_local(const struct gprs_ns2_vc *nsvc);
 const struct osmo_sockaddr *gprs_ns2_ip_bind_sockaddr(struct gprs_ns2_vc_bind *bind);
 int gprs_ns2_is_ip_bind(struct gprs_ns2_vc_bind *bind);
 int gprs_ns2_ip_bind_set_dscp(struct gprs_ns2_vc_bind *bind, int dscp);