feat(esp_libc): add full support for picolibc

examples/network/simple_sniffer/main/cmd_sniffer.c

@@ -7,6 +7,7 @@
 */
 #include <string.h>
 #include <stdlib.h>
+#include <sys/time.h>
 #include "argtable3/argtable3.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"

examples/openthread/ot_sleepy_device/deep_sleep/main/esp_ot_sleepy_device.c

@@ -16,6 +16,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <string.h>
+#include <sys/time.h>
 #include "esp_err.h"
 #include "esp_event.h"
 #include "esp_log.h"

examples/storage/fatfs/fatfsgen/main/fatfsgen_example_main.c

@@ -7,6 +7,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <time.h>
 #include "esp_vfs.h"
 #include "esp_vfs_fat.h"
 #include "esp_err.h"