board/qemu-i386: cleanup doxygen headers

- fixed doxygen group name
- fixed some minor formatting
- added missing file description

boards/qemu-i386/include/board.h

@@ -17,7 +17,9 @@
  */
 
 /**
- * @ingroup     x86
+ * @defgroup    boards_qemu-i386 qemu-i386
+ * @ingroup     boards
+ * @brief       Dummy board to run x86 port in QEMU
  * @{
  *
  * @file

boards/qemu-i386/include/cpu-conf.h

@@ -17,11 +17,12 @@
  */
 
 /**
- * CPU-specific defines for qemu-i386.
+ * @ingroup     boards_qemu-i386
- *
- * @ingroup x86
  * @{
+ *
  * @file
+ * @brief       CPU-specific defines for qemu-i386
+ *
  * @author      René Kijewski <rene.kijewski@fu-berlin.de>
  */
 

boards/qemu-i386/x86_board_init.c

@@ -17,7 +17,7 @@
  */
 
 /**
- * @ingroup     x86
+ * @ingroup     boards_qemu-i386
  * @{
  *
  * @file

boards/qemu-i386/x86_board_lpm.c

@@ -17,7 +17,7 @@
  */
 
 /**
- * @ingroup     x86
+ * @ingroup     boards_qemu-i386
  * @{
  *
  * @file