PPC PMAC driver
The g5 support code broke some earlier models unfortunately as those
bail out early from the detect function, before the point where I added
the code to locate the PCI device for use with DMA allocations.

This patch fixes it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>