PA-RISC firmware needs a hwpath which can be constructed from a pci_dev
or a parisc_device.  Previously we've known what type of device we had,
but when using sysfs we have to figure it out.
Signed-off-by: Thibaut VARENE <varenet@parisc-linux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>