[PATCH] powerpc: document new interrupt-array property

[Yoder Stuart-B08248]

> I'd rather write it like
> 
> >       interrupts        = < a 4   b 4   0 4   1 4   2 4 >
> >       interrupt-parents = <&UIC0 &UIC0 &UIC1 &UIC1 &UIC1>
> 

Segher, with your proposal here of an interrupt-parents property
is this really keeping with the normal OF way of representing
property values?

Examples exists where one property tells you how to interpret
or decode another (e.g. #address-cells), but your proposal we
have two distinct properties each with values that together
provide the complete 'value' (interrupt parent + interrupt
specifier).  Is there any precedent for this approach?

I think I'd rather see all the information encoded in
one value.

Stuart