fix bug: init soft timer thread

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@574 bbd45198-f89e-11dd-88c7-29a3b14d5316

bsp/lpc2478/startup.c

@@ -10,6 +10,7 @@
  * Change Logs:
  * Date           Author       Notes
  * 2008-12-11     xuxinming    first version
+ * 2010-4-3       LiJin        add init soft timer thread 
  */
 
 #include <rthw.h>
@@ -89,6 +90,9 @@ void rtthread_startup(void)
 	finsh_set_device("uart1");
 #endif
 	
+	/* init soft timer thread */
+	rt_system_timer_thread_init();
+
 	/* init idle thread */
 	rt_thread_idle_init();