SNTP: backport espressif sntp api for lwip2 (#7097)

Author: d-a-v

cores/esp8266/time.cpp

@@ -78,13 +78,31 @@ int clock_gettime(clockid_t unused, struct timespec *tp)
 #define sntp_real_timestamp sntp_get_current_timestamp()
 #endif
 
-#if LWIP_VERSION_MAJOR == 2
-// backport api
+#if LWIP_VERSION_MAJOR != 1
+
+// backport Espressif api
+
 bool sntp_set_timezone_in_seconds (int32_t timezone_sec)
 {
     configTime(timezone_sec, 0, sntp_getservername(0), sntp_getservername(1), sntp_getservername(2));
     return true;
 }
+
+bool sntp_set_timezone(sint8 timezone_in_hours)
+{
+    return sntp_set_timezone_in_seconds(3600 * ((int)timezone_in_hours));
+}
+
+char* sntp_get_real_time(time_t t)
+{
+    return ctime(&t);
+}
+
+uint32 sntp_get_current_timestamp()
+{
+    return sntp_real_timestamp;
+}
+
 #endif
 
 time_t time(time_t * t)