[PATCH] powerpc: document new interrupt-array property

[Yoder Stuart-B08248]

> > If this is a one-off situation it doesn't warrant a new
> > general property.  However, if it becomes common enough
> > a simpler representation will benefit developers.
> 
> Sure.  But in that case, it would be a lot better to
> try to come up with something new that can handle the
> general case (or many many more cases at least).

What is the general case you are referring to here?  What
other cases and scenarios can you imagine?

Stuart