!79 将NORETURN声明放到函数前，KEIL不支持放在函数后

Merge pull request !79 from Caoruihong/fix_noreturn

kernel/arch/include/los_context.h

@@ -82,7 +82,7 @@ extern VOID *HalTskStackInit(UINT32 taskID, UINT32 stackSize, VOID *topStack);
  * <ul><li>los_hw.h: the header file that contains the API declaration.</li></ul>
  * @see None.
  */
-LITE_OS_SEC_TEXT_MINOR VOID HalSysExit(VOID) NORETURN;
+LITE_OS_SEC_TEXT_MINOR NORETURN VOID HalSysExit(VOID);
 
 /* *
  * @ingroup  los_context

kernel/include/los_task.h

@@ -501,8 +501,8 @@ extern VOID LOS_Msleep(UINT32 mSecs);
  * @see
  */
 extern UINT32 LOS_Start(VOID);
-extern VOID LOS_Reboot(VOID) NORETURN;
-extern VOID LOS_Panic(const CHAR *fmt, ...) NORETURN;
+extern NORETURN VOID LOS_Reboot(VOID);
+extern NORETURN VOID LOS_Panic(const CHAR *fmt, ...);
 
 
 /**