pseries: Support PCI extended config space in RTAS calls

pseries: Support PCI extended config space in RTAS calls

On the pseries machine (which expexts a paravirtualized guest), guest
access to PCI config space is via host-provided RTAS functions.  This
patch extends these RTAS functions to permit access to PCI extended
config space, as specified in PAPR.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>