Availability of the IOMMUFD backend can now be fully determined at
runtime and the ifdef check was a build time protection (for PPC not
supporting it mostly).
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>