[POWERPC] EEH: capture and log pci state on error

If an EEH event is observed, capture PCI config space info about
the device, wrap it up and pass it to the event logger.  This
pach just slots in the basic logging function. A later patch
will provide for more through data gathering.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>