serial: 8250_exar: add support for Advantech 2 port card with Device ID 0x0018

serial: 8250_exar: add support for Advantech 2 port card with Device ID 0x0018

The Advantech 2-port serial card with PCI vendor=0x13fe and device=0x0018
has a 'XR17V35X' chip installed on the circuit board. Therefore, this
driver can be used instead of theu outdated out-of-tree driver from the
manufacturer.

Signed-off-by: Florian Eckert <fe@dev.tdt.de>
Cc: stable <stable@kernel.org>
Link: https://patch.msgid.link/20250924134115.2667650-1-fe@dev.tdt.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>