deprecate osmo_bts_feature_name(), add osmo_bts_features_desc()

The function osmo_bts_feature_name() is ill-named for two reasons:
- it returns descriptive text instead of just a string representation of
  the name.
- The enum is named "osmo_bts_features", so the function name lacks the
  "s" for "features".

Rationale: An upcoming patch adds a function to return just the name,
properly called osmo_bts_features_name(), so deprecate the weirdly named
one first.

Change-Id: I9dfdb5e81037b6000effbd340af4e5db0dcfd69c
diff --git a/include/osmocom/gsm/bts_features.h b/include/osmocom/gsm/bts_features.h
index ac2c760..b174d3f 100644
--- a/include/osmocom/gsm/bts_features.h
+++ b/include/osmocom/gsm/bts_features.h
@@ -34,7 +34,11 @@
 
 extern const struct value_string osmo_bts_features_descs[];
 
-const char *osmo_bts_feature_name(enum osmo_bts_features feature);
+static inline const char *osmo_bts_features_desc(enum osmo_bts_features val)
+{ return get_value_string(osmo_bts_features_descs, val); }
+
+const char *osmo_bts_feature_name(enum osmo_bts_features feature)
+	OSMO_DEPRECATED("Use osmo_bts_features_desc() instead");
 
 static inline int osmo_bts_set_feature(struct bitvec *features, enum osmo_bts_features feature)
 {