add alarm

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2374 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/drivers/include/rtdevice.h

@@ -138,7 +138,10 @@ rt_err_t rt_data_queue_peak(struct rt_data_queue *queue,
 void rt_data_queue_reset(struct rt_data_queue *queue);
 
 #ifdef RT_USING_RTC
-#include "drivers/rtc.h"
+#include "drivers/rtc.h"
+#ifdef RT_USING_ALARM
+#include "drivers/alarm.h"
+#endif
 #endif /* RT_USING_RTC */
 
 #ifdef RT_USING_SPI