staging: lustre: move ioctls to lustre_ioctl.h

Move ioctl definitions and related functions from lustre_dlm.h,
lustre_lib.h, obd.h, to lustre_ioctl.h. Replace the definitions of
retired ioctls with comment.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4961
Reviewed-on: http://review.whamcloud.com/10139
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Robert Read <robert.read@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>