Maintain legacy RTOS behavior before mbed-5

Fork of mbed-rtos by mbed official

Revision:
123:58563e6cba1e
Parent:
118:6635230e06ba
--- a/rtx/TARGET_CORTEX_M/rt_OsEventObserver.h	Wed Nov 09 12:22:14 2016 -0600
+++ b/rtx/TARGET_CORTEX_M/rt_OsEventObserver.h	Mon Nov 14 17:14:42 2016 -0600
@@ -1,3 +1,6 @@
+
+/** \addtogroup rtos */
+/** @{*/
 /*----------------------------------------------------------------------------
  *      CMSIS-RTOS  -  RTX
  *----------------------------------------------------------------------------
@@ -56,3 +59,5 @@
 #endif
 
 #endif
+
+/** @}*/