删除没有用的预编译，在新版的IAR中此已经不需要了

对time函数增加RT_WEAK

components/libc/compilers/common/time.c

@@ -160,16 +160,7 @@ char* ctime(const time_t *timep)
  * @return time_t return timestamp current.
  *
  */
-#if defined (__IAR_SYSTEMS_ICC__) &&  (__VER__) >= 6020000 /* for IAR 6.2 later Compiler */
-#pragma module_name = "?time"
-#if _DLIB_TIME_USES_64
-time_t __time64(time_t *t) 
-#else
-time_t __time32(time_t *t) 
-#endif
-#else /* Keil & GCC */
-time_t time(time_t *t)
-#endif
+RT_WEAK time_t time(time_t *t)
 {
     time_t time_now = 0;