[SERIAL] serial_cs: handle Nokia multi->single port bodge via config quirk

According to the existing code, Nokia only make single-port cards,
but are detected as multi-port cards.  Handle this in roughly the
same way via the config quirk - forcing it to be a real single port
card (info->multi=0) changes the way we allocate the IO memory,
which might stop the card working.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>