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/gsm/rsl.h b/include/osmocom/gsm/rsl.h
index 5da6180..93e27a1 100644
--- a/include/osmocom/gsm/rsl.h
+++ b/include/osmocom/gsm/rsl.h
@@ -17,13 +17,13 @@
 
 extern const struct tlv_definition rsl_att_tlvdef;
 
-/*! \brief Parse RSL TLV structure using \ref tlv_parse */
+/*! Parse RSL TLV structure using \ref tlv_parse */
 #define rsl_tlv_parse(dec, buf, len)     \
 			tlv_parse(dec, &rsl_att_tlvdef, buf, len, 0, 0)
 
 extern const struct tlv_definition rsl_ipac_eie_tlvdef;
 
-/*! \brief Parse RSL IPAC EIE TLV structure using \ref tlv_parse */
+/*! Parse RSL IPAC EIE TLV structure using \ref tlv_parse */
 #define rsl_ipac_eie_tlv_parse(dec, buf, len)     \
 			tlv_parse(dec, &rsl_ipac_eie_tlvdef, buf, len, 0, 0)
 
@@ -58,7 +58,7 @@
 
 extern const struct value_string rsl_act_type_names[];
 
-/*! \brief Return a human readable name for GSM 08.58 RSL_ACT_* constants. */
+/*! Return a human readable name for GSM 08.58 RSL_ACT_* constants. */
 static inline const char *rsl_act_type_name(uint8_t act_type)
 {
 	return get_value_string(rsl_act_type_names, act_type);