parisc: provide pci_mmap_page_range() for parisc

pci_mmap_page_range() is needed for X11-server support on C8000 with ATI
FireGL card.

Signed-off-by Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Helge Deller <deller@gmx.de>