util: Delete util/batch, util/pbs, and util qdo.

util: Delete util/batch, util/pbs, and util qdo.

The util/pbs directory has a set of python scripts which were written to
submit jobs to the PBS pool at the University of Michigan. They aren't
incredibly specialized for that environment, but they do have a little
bit of hard coding which, for instance, uses paths which are only
meaningful there.

The util/batch directory was added alongside a seemingly unrelated
change (perhaps by accident?) and is a slightly updated copy of util/pbs
which also (or instead?) supports OAR.

The qdo script seems to be a script for managing job queues on PBS
and/or OAR, and is also tuned to the UofM environment, for instance
insisting that a path starts with /n/poolfs so that files are available
on an NFS volume shared with the pool.

All three of these scripts could potentially be useful with modification
in a similar environment, but also all three are unmaintained. The
environment in UofM may no longer actually match the expectations of
these scripts, and even if it does/did, gem5 may no longer be 100%
compatible with them.

If these scripts sit in util not being used by anyone, they add clutter
and complexity without adding any value. If someone really needs to know
what was once in them, they can be recovered from revision control.

Change-Id: I0192bd119893f7a41fcb820f4cf408609b03cd27
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30957
Reviewed-by: Steve Reinhardt <stever@gmail.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>