error ASYNC_CTS_FLOW undeclared

  CC      drivers/tty/serial/ingenic_uart.o
drivers/tty/serial/ingenic_uart.c: In function 'init_hw_stopped_status':
drivers/tty/serial/ingenic_uart.c:586:20: error: 'ASYNC_CTS_FLOW' undeclared (first use in this function); did you mean 'ASYNC_SAK'?
  if (tport.flags & ASYNC_CTS_FLOW) {
                    ^~~~~~~~~~~~~~
                    ASYNC_SAK
drivers/tty/serial/ingenic_uart.c:586:20: note: each undeclared identifier is reported only once for each function it appears in
make[3]: *** [drivers/tty/serial/ingenic_uart.o] Error 1
make[2]: *** [drivers/tty/serial] Error 2

drivers/tty/serial/ingenic_uart.c
@@ -583,7 +583,7 @@ static void init_hw_stopped_status(struct uart_port *uport)
        struct tty_port tport = uport->state->port;
        struct tty_struct *tty = tport.tty;

-       if (tport.flags & ASYNC_CTS_FLOW) {
+       if (tty_port_cts_enabled(&tport)) {