Wrap variable missed by the python script.

Signed-off-by: Mateusz Starzyk <mateusz.starzyk@mobica.com>
diff --git a/include/mbedtls/timing.h b/include/mbedtls/timing.h
index 9a8b1e0..7669bb9 100644
--- a/include/mbedtls/timing.h
+++ b/include/mbedtls/timing.h
@@ -52,7 +52,7 @@
  */
 typedef struct mbedtls_timing_delay_context
 {
-    struct mbedtls_timing_hr_time   timer;
+    struct mbedtls_timing_hr_time   MBEDTLS_PRIVATE(timer);
     uint32_t                        MBEDTLS_PRIVATE(int_ms);
     uint32_t                        MBEDTLS_PRIVATE(fin_ms);
 } mbedtls_timing_delay_context;