gprs_ns2: add gprs_ns2_nse_sns_remote() returns the initial SNS address

Allows the PCU to get the SNS remote address.

Change-Id: I54f110acc3acccb362f6e554324d08cc42b7c328
diff --git a/src/gb/libosmogb.map b/src/gb/libosmogb.map
index f542496..e6557b7 100644
--- a/src/gb/libosmogb.map
+++ b/src/gb/libosmogb.map
@@ -102,6 +102,7 @@
 gprs_ns2_ll_str_c;
 gprs_ns2_nse_by_nsei;
 gprs_ns2_nse_nsei;
+gprs_ns2_nse_sns_remote;
 gprs_ns2_nsvc_by_nsvci;
 gprs_ns2_nsvc_by_sockaddr;
 gprs_ns2_recv_prim;