[PATCH] DTC: Rewrite the propdata and propdataprefix rules.

[Jon Loeliger]

So, like, the other day Jon Loeliger mumbled:
> 
> After staring at these two rules for a bit, and not quite
> groking them, I rewrote them into something I think is a
> bit clearer.  With any luck, it's the same language still.
> 
> Signed-off-by: Jon Loeliger <jdl at freescale.com>
> ---
> 
> You be the judge too!

Yeah, so, I botched this one.  It's NOT the same
language, so don't apply it or think about it at all...

jdl