pch_uart: Fix hw-flow control issue

Using hardware flow control,
currently, register of the control-bit(AFE) is not set.
This patch fixes the issue.
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.lapis-semi.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/tty/serial/pch_uart.c

@@ -1280,6 +1280,7 @@ static void pch_uart_set_termios(struct uart_port *port,
 	if (rtn)
 		goto out;
 
+	pch_uart_set_mctrl(&priv->port, priv->port.mctrl);
 	/* Don't rewrite B0 */
 	if (tty_termios_baud_rate(termios))
 		tty_termios_encode_baud_rate(termios, baud, baud);