Local bus binding

[Segher Boessenkool]

> Segher,
> Kumar said he wants an ack from you on the local bus node binding 
> before he applies it -- can you review this patch?
>
> http://patchwork.ozlabs.org/linuxppc/patch?id=13591

As discussed on IRC a bit already...

- All three "should"s should be "typically"s.
- The relevant values for "compatible" should be included.
- It is wrong to require the localbus node to be a direct child of
   the root node.  This isn't in the binding /per se/, but both the
   commit message and the code do mention it.


Segher