[POWERPC] maple: Match "pcie" name for CPC945

Some firmwares have "pcie" for the "name" property of the CPC945 PCI
Express host bridge.  Check for "pcie" in addition to "pci" so we
don't miss it.

Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>