fix comments and time_t type issues

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 9703fcb..ca727f9 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -1185,7 +1185,7 @@
 #endif /* MBEDTLS_SHA256_C  */
 
 #if defined(MBEDTLS_HAVE_TIME) && defined(MBEDTLS_SSL_CLI_C)
-    time_t MBEDTLS_PRIVATE(ticket_received);                /*!< time ticket was received */
+    mbedtls_time_t MBEDTLS_PRIVATE(ticket_received);        /*!< time ticket was received */
 #endif /* MBEDTLS_HAVE_TIME && MBEDTLS_SSL_CLI_C */
 
 #endif /*  MBEDTLS_SSL_PROTO_TLS1_3 && MBEDTLS_SSL_SESSION_TICKETS */