abis_nm: remove abis_nm_obj_class_name / abis_nm_adm_state_name

and export the underlying raw value_string arrays instead:
abis_nm_obj_class_names / abis_nm_adm_state_names.

This permits the caller to use get_string_value() as well as
get_value_string().
diff --git a/include/osmocom/gsm/abis_nm.h b/include/osmocom/gsm/abis_nm.h
index fc096dc..e7c3769 100644
--- a/include/osmocom/gsm/abis_nm.h
+++ b/include/osmocom/gsm/abis_nm.h
@@ -9,16 +9,17 @@
 const enum abis_nm_msgtype abis_nm_sw_load_msgs[9];
 const enum abis_nm_msgtype abis_nm_nacks[33];
 
+const struct value_string abis_nm_obj_class_names[];
+const struct value_string abis_nm_adm_state_names[];
+
 const char *abis_nm_nack_cause_name(uint8_t cause);
 const char *abis_nm_nack_name(uint8_t nack);
 const char *abis_nm_event_type_name(uint8_t cause);
 const char *abis_nm_severity_name(uint8_t cause);
 const struct tlv_definition abis_nm_att_tlvdef;
-const char *abis_nm_obj_class_name(uint8_t oc);
 const char *abis_nm_opstate_name(uint8_t os);
 const char *abis_nm_avail_name(uint8_t avail);
 const char *abis_nm_test_name(uint8_t test);
-const char *abis_nm_adm_state_name(uint8_t adm);
 void abis_nm_debugp_foh(int ss, struct abis_om_fom_hdr *foh);
 
 #endif /* _OSMO_GSM_ABIS_NM_H */