spec: allow all archs in Fedora

As long as Vdsm is in Fedora, its Fedora build must abide to the rules
and allow building on all supported Fedora architectures.

Change-Id: I35b4c2e141735351b1069070b01893dc1bdf7043
Bug-Url: https://bugzilla.redhat.com/1141669
Signed-off-by: Dan Kenigsberg <danken@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/33368
Reviewed-by: Federico Simoncelli <fsimonce@redhat.com>
Reviewed-by: Antoni Segura Puimedon <asegurap@redhat.com>
Reviewed-by: Nir Soffer <nsoffer@redhat.com>