Relocate assignment of x86 get_arch_id to have all hooks in one place.
Reviewed-by: NJens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: NLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NAndreas Färber <afaerber@suse.de>