Do not use timezone at all for Q_OS_INTEGRITY.

Change-Id: I3674b86b65a6ec47c89cc4f49e00361e9b87a7c3
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qdatetime.cpp

@@ -2178,6 +2178,8 @@ static int qt_timezone()
         // - It also takes DST into account, so we need to adjust it to always
         //   get the Standard Time offset.
         return -t.tm_gmtoff + (t.tm_isdst ? SECS_PER_HOUR : 0L);
+#elif defined(Q_OS_INTEGRITY)
+        return 0;
 #else
         return timezone;
 #endif // Q_OS_WIN