serial: 8250_fintek: Disable delays for ports != 0

According to the datasheet, only the first port supports delay before
send and delay after send.

Reported-by: "Ji-Ze Hong (Peter Hong)" <hpeter@gmail.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_fintek.c

@@ -212,6 +212,12 @@ static int fintek_8250_rs485_config(struct uart_port *port,
 	rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
 			SER_RS485_RTS_AFTER_SEND;
 
+	/* Only the first port supports delays */
+	if (pdata->index) {
+		rs485->delay_rts_before_send = 0;
+		rs485->delay_rts_after_send = 0;
+	}
+
 	if (rs485->delay_rts_before_send) {
 		rs485->delay_rts_before_send = 1;
 		config |= TXW4C_IRA;