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/include/osmocom/gprs/gprs_rlc.h b/include/osmocom/gprs/gprs_rlc.h
index d34d49b..5765281 100644
--- a/include/osmocom/gprs/gprs_rlc.h
+++ b/include/osmocom/gprs/gprs_rlc.h
@@ -2,14 +2,14 @@
 
 #include <stdint.h>
 
-/*! \brief Structure for CPS coding and puncturing scheme (TS 04.60 10.4.8a) */
+/*! Structure for CPS coding and puncturing scheme (TS 04.60 10.4.8a) */
 struct egprs_cps {
 	uint8_t bits;
 	uint8_t mcs;
 	uint8_t p[2];
 };
 
-/*! \brief CPS puncturing table selection (TS 04.60 10.4.8a) */
+/*! CPS puncturing table selection (TS 04.60 10.4.8a) */
 enum egprs_cps_punc {
 	EGPRS_CPS_P1,
 	EGPRS_CPS_P2,
@@ -17,7 +17,7 @@
 	EGPRS_CPS_NONE = -1,
 };
 
-/*! \brief EGPRS header types (TS 04.60 10.0a.2) */
+/*! EGPRS header types (TS 04.60 10.0a.2) */
 enum egprs_hdr_type {
         EGPRS_HDR_TYPE1,
         EGPRS_HDR_TYPE2,