The Mobility docking station provides a PCI-based parallel port.  Since the
docking station connects via Cardbus, such devices are removable. 
Therefore, track which parallel ports are registered to each PCI device,
and remove them when the PCI device is removed.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>