In uart_set_rs485_config() the serial core already clamps the RTS delays.
It also assigns the passed serial_rs485 struct to the uart port.

So remove these tasks from the drivers rs485_config() function to avoid
redundancy.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Link: https://lore.kernel.org/r/20220410104642.32195-6-LinoSanfilippo@gmx.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>