avutil/xtea: add Doxy @file and group

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavutil/xtea.c

@@ -21,6 +21,13 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+/**
+ * @file
+ * @brief XTEA 32-bit implementation
+ * @author Samuel Pitoiset
+ * @ingroup lavu_xtea
+ */
+
 #include "avutil.h"
 #include "common.h"
 #include "intreadwrite.h"

libavutil/xtea.h

@@ -25,6 +25,8 @@
 #include <stdint.h>
 
 /**
+ * @file
+ * @brief Public header for libavutil XTEA algorithm
  * @defgroup lavu_xtea XTEA
  * @ingroup lavu_crypto
  * @{