add osmo_cgi_name()

This will be used by cell idenitifier list code, like upcoming neighbor_ident
VTY in osmo-bsc and regression tests.

Change-Id: Iebc5cdf61b697b1603900993fc265af3eca0cedf
diff --git a/include/osmocom/gsm/gsm23003.h b/include/osmocom/gsm/gsm23003.h
index 02e7971..fd4f369 100644
--- a/include/osmocom/gsm/gsm23003.h
+++ b/include/osmocom/gsm/gsm23003.h
@@ -99,6 +99,8 @@
 const char *osmo_plmn_name(const struct osmo_plmn_id *plmn);
 const char *osmo_plmn_name2(const struct osmo_plmn_id *plmn);
 const char *osmo_lai_name(const struct osmo_location_area_id *lai);
+const char *osmo_cgi_name(const struct osmo_cell_global_id *cgi);
+const char *osmo_cgi_name2(const struct osmo_cell_global_id *cgi);
 
 void osmo_plmn_to_bcd(uint8_t *bcd_dst, const struct osmo_plmn_id *plmn);
 void osmo_plmn_from_bcd(const uint8_t *bcd_src, struct osmo_plmn_id *plmn);