gprs_bssgp_rim: add value strings for enum bssgp_rim_routing_info_discr

Change-Id: Idd06d2e3df0d60409a89a474018a9d97f7772090
Related: SYS#5103
diff --git a/include/osmocom/gprs/gprs_bssgp_rim.h b/include/osmocom/gprs/gprs_bssgp_rim.h
index 48bf047..0810c8e 100644
--- a/include/osmocom/gprs/gprs_bssgp_rim.h
+++ b/include/osmocom/gprs/gprs_bssgp_rim.h
@@ -33,6 +33,12 @@
 	BSSGP_RIM_ROUTING_INFO_EUTRAN,
 };
 
+extern const struct value_string bssgp_rim_routing_info_discr_strs[];
+
+/*! Obtain a human-readable string for NACC Cause code */
+static inline const char *bssgp_rim_routing_info_discr_str(enum bssgp_rim_routing_info_discr val)
+{ return get_value_string(bssgp_rim_routing_info_discr_strs, val); }
+
 /*! BSSGP RIM Routing information, see also 3GPP TS 48.018, section 11.3.70 */
 struct bssgp_rim_routing_info {
 	enum bssgp_rim_routing_info_discr discr;