gprs_bssgp_rim: add functions to convert a RIM-RI to a string

RIM routing formation structs can contain different variants of address
identifiers, so it is difficult for an API user to pick the _name()
function to generate a human readable string. Lets add
bssgp_rim_ri_name() and bssgp_rim_ri_name_buf() to make printing a
routing identifier easier.

Change-Id: Idca6bdccffe663aea71a0183ca3ea5bb5b59e702
Related: SYS#5103
diff --git a/src/gb/libosmogb.map b/src/gb/libosmogb.map
index b4d7fdb..c6bbc78 100644
--- a/src/gb/libosmogb.map
+++ b/src/gb/libosmogb.map
@@ -35,6 +35,8 @@
 bssgp_parse_rim_ri;
 bssgp_ran_inf_app_id_strs;
 bssgp_rim_routing_info_discr_strs;
+bssgp_rim_ri_name_buf;
+bssgp_rim_ri_name;
 bssgp_set_bssgp_callback;
 bssgp_tx_bvc_block;
 bssgp_tx_bvc_reset;