[POWERPC] Celleb: update for PCI

This adds support for the PCI bus on Celleb with new "I/O routines
for PowerPC."  External PCI on Celleb must do explicit synchronization
with devices (Bus has no automatic synchronization feature).

Signed-off-by: Kou Ishizaki <Kou.Ishizaki@toshiba.co.jp>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>