lxd/qemu: Restrict NUMA layout to x86_64
lxd/qemu: Restrict NUMA layout to x86_64

At least on aarch64, core_id doesn't appear to be supported.
So this will need more testing and potentially a different approach on
some architectures.

Signed-off-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>

hallyn/lxd,hallyn/lxd,atxwebs/lxd,Skarlso/lxd,hallyn/lxd,stgraber/lxd,stgraber/lxd,mjeanson/lxd,atxwebs/lxd,Skarlso/lxd,lxc/lxd,atxwebs/lxd,stgraber/lxd,lxc/lxd,stgraber/lxd,atxwebs/lxd,lxc/lxd,hallyn/lxd,mjeanson/lxd,stgraber/lxd,Skarlso/lxd,lxc/lxd,hallyn/lxd,stgraber/lxd,Skarlso/lxd,mjeanson/lxd,lxc/lxd,hallyn/lxd,lxc/lxd,lxc/lxd,stgraber/lxd