Update doxygen annotations in libosmocore
This adds and improves doxygen API descriptions all over libosmocore,
reducing the 'white spots' that don't have any documentation.
diff --git a/src/prim.c b/src/prim.c
index c2e7198..3f41c41 100644
--- a/src/prim.c
+++ b/src/prim.c
@@ -1,6 +1,8 @@
#include <osmocom/core/utils.h>
#include <osmocom/core/prim.h>
+/*! \brief human-readable string mapping for
+ * \ref osmo_prim_operation */
const struct value_string osmo_prim_op_names[5] = {
{ PRIM_OP_REQUEST, "request" },
{ PRIM_OP_RESPONSE, "response" },