modem sleep: add wifi power save callback to idle task

components/esp32/task_wdt.c

@@ -29,6 +29,7 @@
 #include "soc/timer_group_struct.h"
 #include "soc/timer_group_reg.h"
 #include "esp_log.h"
+#include "esp_wifi_internal.h"
 
 #include "esp_task_wdt.h"
 
@@ -167,7 +168,8 @@ void vApplicationIdleHook(void) {
     if (xPortGetCoreID()!=0) return;
 #endif
     esp_task_wdt_feed();
+    esp_wifi_ps_idle_cb();
 }
 #endif
 
-#endif
+#endif