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/gsm/comp128.c b/src/gsm/comp128.c
index cb3a309..78f0e07 100644
--- a/src/gsm/comp128.c
+++ b/src/gsm/comp128.c
@@ -73,7 +73,7 @@
  */
 
 /*! \file comp128.c
- *  \brief COMP128 v1; common/old GSM Authentication Algorithm (A3/A8)
+ *  COMP128 v1; common/old GSM Authentication Algorithm (A3/A8)
  */
 
 /* The compression tables (just copied ...) */
@@ -192,7 +192,7 @@
 		x[(i>>3)+16] |= bits[(i*17) & 127] << (7-(i&7));
 }
 
-/*! \brief Perform COMP128v1 algorithm
+/*! Perform COMP128v1 algorithm
  *  \param[in] ki Secret Key K(i) of subscriber
  *  \param[in] rand Random Challenge
  *  \param[out] sres user-supplied buffer for storing computed SRES value
@@ -242,7 +242,7 @@
 }
 
 
-/*! \brief Perform COMP128v1 algorithm
+/*! Perform COMP128v1 algorithm
  *  \param[in] ki Secret Key K(i) of subscriber
  *  \param[in] rand Random Challenge
  *  \param[out] sres user-supplied buffer for storing computed SRES value