serial: ar933x: Remove superfluous code in ar933x_config_rs485()

In ar933x_config_rs485() the check for the RTS GPIO is not needed since in
case the GPIO is not available at driver init ar933x_no_rs485 is assigned
to port->rs485_supported and this function is never called. So remove the
check.

Also in uart_set_rs485_config() the serial core already assigns the passed
serial_rs485 struct to the uart port. So remove the assignment in the
drivers rs485_config() function to avoid redundancy.

Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Link: https://lore.kernel.org/r/20220710164442.2958979-3-LinoSanfilippo@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/ar933x_uart.c

@@ -583,15 +583,6 @@ static const struct uart_ops ar933x_uart_ops = {
 static int ar933x_config_rs485(struct uart_port *port, struct ktermios *termios,
 				struct serial_rs485 *rs485conf)
 {
-	struct ar933x_uart_port *up =
-		container_of(port, struct ar933x_uart_port, port);
-
-	if ((rs485conf->flags & SER_RS485_ENABLED) &&
-	    !up->rts_gpiod) {
-		dev_err(port->dev, "RS485 needs rts-gpio\n");
-		return 1;
-	}
-	port->rs485 = *rs485conf;
 	return 0;
 }