LU-2675 lustre: remove linux/obd_support.h

LU-2675 lustre: remove linux/obd_support.h

Remove the unnecessary header lustre/include/linux/obd_support.h. In
lustre/include/obd_support.h assume a kernel build.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I3bead5495b7f4a08183653f2e1eb06d429543091
Reviewed-on: http://review.whamcloud.com/11931
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>