Release v1.5.2 on 2021-09-24.

1. e08da97 Fix/Update copyright notices; Add SPDX annotation by Harald Welte · 7 years ago
2. 7166094 [doc] Expand Doxuygen documentation for osmo_prim by Harald Welte · 7 years ago
3. 17518fe doxygen: unify use of \file across the board by Neels Hofmeyr · 7 years ago
4. 87e4550 doxygen: enable AUTOBRIEF, drop \brief by Neels Hofmeyr · 7 years ago
5. acd08fe Add struct osmo_prim_event_map and osmo_event_for_prim() by Harald Welte · 7 years ago
6. 2d2e2cc Update doxygen annotations in libosmocore by Harald Welte · 8 years ago
7. a2db75f Add osmo_prim_op_names[] symbol and _SAP_SS7_BASE define by Harald Welte · 8 years ago