qemu: Add conditions for qemu-kvm use on ppc64
qemu: Add conditions for qemu-kvm use on ppc64

qemu-kvm can be used to run ppc64 guests on ppc64le hosts and vice
versa, since the hardware is actually the same and the endianness
is chosen by the guest kernel.

Up until now, however, libvirt didn't allow the use of qemu-kvm
to run guests if their endianness didn't match the host's.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1267882

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