Patch from Zwane Mwaikambo, fixed by rmk, comments by rmk.

SIIG cards have parallel ports in addition to serial ports.  We therefore
probe the cards in parport_serial.c and call the serial specific probe
functions in 8250_pci.c

This is the second half of a patch that was applied in 2.5.50 to
parport_serial by others without the corresponding 8250_pci.c changes.