ppc64 packages that did not build for dist-fc7

[orion at cora.nwra.com]

> As part of the merge, we bootstrapped and imported Extras for ppc64.
>
> Not all packages built correctly. Logs of the failures are available at:
> 	http://people.redhat.com/notting/ppc64-rebuild/
>
> plplot-5.7.3-2.fc7

Apparently this is because of a missing gcc-gnat, but I don't see that in
the list of failed builds.  Missing plplot causes other problems (gdl for
one)

- Orion