LU-2675 build: remove Darwin "support"

Remove the Darwin "support" code. It's not maintained or used.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I56ee7788d55465495815c4f8655e986dd5a51d00
Reviewed-on: http://review.whamcloud.com/11423


Reviewed-by: frank zago <fzago@cray.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Tested-by: Jenkins
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>