[POWERPC] Dont look for class-code in pci children

Looking for class-code in PCI children breaks with direct slots. Lets
just count all children.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>