Enable build on armv6+
Enable build on armv6+

The following patch enables it to build on ARM platforms that support
atomics. Tested on an armv7hl on an ARMv7 device running Fedora 18. Using
firefox connecting to a RHEV-M instance I could launch consoles in
spice-xpi and login so basic support works!

Resolves: rhbz#613529

ya-mouse/spice,freedesktop-unofficial-mirror/spice__spice,Fantu/spice,alon/spice-server,elmarco/spice,freedesktop-unofficial-mirror/spice__spice,ya-mouse/spice,mathslinux/spice,mathslinux/spice,elmarco/spice,mathslinux/spice,alon/spice-server,SPICE/spice,mathslinux/spice,elmarco/spice,freedesktop-unofficial-mirror/spice__spice,SPICE/spice,freedesktop-unofficial-mirror/spice__spice,fgouget/spice,SPICE/spice,fgouget/spice,mathslinux/spice,freedesktop-unofficial-mirror/spice__spice,alon/spice-server,fgouget/spice,alon/spice-server,fgouget/spice,ya-mouse/spice,Fantu/spice,elmarco/spice,Fantu/spice,alon/spice-server,Fantu/spice,elmarco/spice