Deorbit AIX-specific QuickStartGuide bits

Deorbit AIX-specific QuickStartGuide bits

Although there are still servers deployed on AIX systems,
there may not be any clients in use, and it is unlikely that
there will be new deployments which require this documentation.

Change-Id: Id6554e120cb01c5d4de5c7de67e74e802b7ea217
Reviewed-on: http://gerrit.openafs.org/11592
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>