Add defines for recent darwin sysctl constants

Add defines for recent darwin sysctl constants

These were accidentally omitted from commit
ab9bb6363ca95f658764fbb9fb68ec88f89a5b3f.

Reviewed-on: http://gerrit.openafs.org/11875
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Reviewed-by: Perry Ruiter <pruiter@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit 9076cbd58dd48801ad212f803f586fdc53d7b886)

Change-Id: I5a2ff768e0faec955c6ed7dafb4231fd3885e5bd
Reviewed-on: http://gerrit.openafs.org/11876
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Perry Ruiter <pruiter@sinenomine.net>
Reviewed-by: Daria Brashear <shadow@your-file-system.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>