add rtc function

Change-Id: I30f58c6c2081d02d70f4519370eef12e7a559d8b
diff --git a/mbtk/liblynq_lib/src/lynq_time.c b/mbtk/liblynq_lib/src/lynq_time.c
index 55f3ef3..8f432f0 100644
--- a/mbtk/liblynq_lib/src/lynq_time.c
+++ b/mbtk/liblynq_lib/src/lynq_time.c
@@ -303,7 +303,8 @@
 // system time set to RTC
 int lynq_set_rtc_time(void)
 {
-    system("hwclock --systohc");
+//    system("hwclock --systohc");
+    system("hwclock -w rtc0");
     return 0;
 }