that's not the proper command. the text you entered was from the help of the setserial command.
You need to enter the commands like this:
setserial /dev/ttyS3 uart XXXXX
where XXXXX is replaced by the UART values, which can be one of the following choices: none, 8250, 16450, 16550, 16550A,16650, 16650V2, 16750, 16850, 16950 and 16954.
Similarly, "* baud_base set base baud rate (CLOCK_FREQ / 16)" is not a command, but a description of what the arguments for setserial's baud_base setting can be. The actual command that people have had success with is:
setserial /dev/ttyS3 baud_base 230400
Here, remember that it might not be ttyS3 for you, you need to find out which tty was activated and therefore, which one you have to use by doing
dmesg | grep tty
just after plugging the card in.
Cheers