doxygen: enable AUTOBRIEF, drop \brief

Especially for short descriptions, it is annoying to have to type \brief for
every single API doc.

Drop all \brief and enable the AUTOBRIEF feature of doxygen, which always takes
the first sentence of an API doc as the brief description.

Change-Id: I11a8a821b065a128108641a2a63fb5a2b1916e87
diff --git a/src/coding/gsm0503_tables.c b/src/coding/gsm0503_tables.c
index 1c85765..32d12ea 100644
--- a/src/coding/gsm0503_tables.c
+++ b/src/coding/gsm0503_tables.c
@@ -27,7 +27,7 @@
 /*! \addtogroup tables
  *  @{
  *
- *  \brief GSM TS 05.03 tables
+ *  GSM TS 05.03 tables
  *
  *  This module contains various tables defining parts of 3GPP TS 05.03
  *  / 45.003, primarily for the purpose of (de)puncturing, interleaving,