[PATCH] libata-acpi: Try and stop all the non PCI devices crashing

For 2.6.20 it mostly used to just not work, for 2.6.21-rc it crashes, this
seems to be down to luck (bad or good). The libata-acpi code needs to
avoid doing PCI work on non-PCI devices. This is one hack although it's
not pretty and perhaps there is a "right" way to check if a struct device
* is PCI ?

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>