fix RTOS SysTick cycle time error caused by DFS
@@ -426,7 +426,7 @@ static void IRAM_ATTR on_freq_update(uint32_t old_ticks_per_us, uint32_t ticks_p
}
#if __XTENSA__
-#if XT_RTOS_TIMER_INT
+#ifdef XT_RTOS_TIMER_INT
/* Calculate new tick divisor */
_xt_tick_divisor = ticks_per_us * MHZ / XT_TICK_PER_SEC;
#endif
