Presently suspend/resume and migration aren't supported on Xen/ARM. As
such this shouldn't ever occur.
Modified to check for ARM instead of !x86, since ARM is where support is
missing. Other Xen architectures might get suspend support sooner.
Submitted by: Elliott Mitchell <ehem+freebsd@m5p.com>
Original implementation: Julien Grall <julien@xen.org>, 2014-01-13 17:41:15