This was intended for the time we had a huge bunch of third
party ppds, those are now long gone.

SGENT42.PS is now the same as SGENPRT.PS since

commit 871d8e0f
Date:   Mon Nov 25 14:13:40 2013 +0000
    Resolves: rhbz#188467 default to Type42

so get rid of that one, leaving just the single SGENPRT.PS
fallback ppd

Change-Id: I851f25b2789b8aa101acd18193cd01e8cded4d09