[PATCH] ppc64: Fix add notifier crashes

The extraction of PCI stuff from struct device_node left some false
assumptions in notifier code.  As a result, dynamic add crashes when
non-PCI nodes are added.  This patch fixes these assumptions.

Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>