Fix build for ESP-IDF v4.0-dev

pandax381 · pandax381 · commit 133646ae43d9 · 2019-06-10T18:31:06.000+09:00
diff --git a/src/mrb_esp32_system.c b/src/mrb_esp32_system.c
@@ -4,6 +4,7 @@
 #include <stdio.h>
 
 #include "esp_system.h"
+#include "esp_sleep.h"
 
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
