[PATCH] restore parport_pc probing on powermac

The last change for partport_pc did fix the common case for all PowerMacs,
but it broke the case for PCI multiport IO cards.  In fact, the config
option CONFIG_PARPORT_PC_SUPERIO=y lead to a hard crash when cups probed
the parport driver.  It enables the winbond and smsc probing.

Remove the PARPORT_BASE check again, parport_pc_find_nonpci_ports() will
take care of it.  All powerpc configs should have
CONFIG_PARPORT_PC_SUPERIO=n, the code did not find anything on the chrp
boards we tested it on.

Tested on a G4/466 with a PCI card:

0001:10:13.0 Serial controller: Timedia Technology Co Ltd PCI2S550 (Dual 16550 UART) (rev 01) (prog-if 02 [16550])
        Subsystem: Timedia Technology Co Ltd Unknown device 5079
        Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping+ SERR- FastB2B-
        Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Interrupt: pin A routed to IRQ 53
      ...