Only set QEMU_CAPS_NO_HPET on x86
Only set QEMU_CAPS_NO_HPET on x86

QEMU only supports it on x86, but we've been assuming it for
all QEMUs when doing QMP capability detection.

https://bugzilla.redhat.com/show_bug.cgi?id=1066145

elmarco/libvirt,jfehlig/libvirt,zippy2/libvirt,nertpinx/libvirt,datto/libvirt,elmarco/libvirt,andreabolognani/libvirt,libvirt/libvirt,datto/libvirt,taget/libvirt,taget/libvirt,rlaager/libvirt,jardasgit/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,elmarco/libvirt,rlaager/libvirt,nertpinx/libvirt,rlaager/libvirt,taget/libvirt,shugaoye/libvirt,agx/libvirt,crobinso/libvirt,shugaoye/libvirt,agx/libvirt,VenkatDatta/libvirt,crobinso/libvirt,jfehlig/libvirt,libvirt/libvirt,crobinso/libvirt,rlaager/libvirt,fabianfreyer/libvirt,taget/libvirt,jardasgit/libvirt,datto/libvirt,fabianfreyer/libvirt,eskultety/libvirt,shugaoye/libvirt,agx/libvirt,jfehlig/libvirt,eskultety/libvirt,zippy2/libvirt,olafhering/libvirt,jardasgit/libvirt,crobinso/libvirt,agx/libvirt,shugaoye/libvirt,zippy2/libvirt,eskultety/libvirt,VenkatDatta/libvirt,elmarco/libvirt,eskultety/libvirt,andreabolognani/libvirt,eskultety/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,elmarco/libvirt,olafhering/libvirt,jfehlig/libvirt,olafhering/libvirt,datto/libvirt,andreabolognani/libvirt,jardasgit/libvirt,agx/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,libvirt/libvirt,andreabolognani/libvirt,taget/libvirt,libvirt/libvirt,olafhering/libvirt,rlaager/libvirt,datto/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,zippy2/libvirt,jardasgit/libvirt,shugaoye/libvirt