configure: factor out adding disas configure Every arch adds its disas configury to both its own config as well config_disas_all. Make a small function do to both at once. Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com> Message-Id: <1440844439-19391-1-git-send-email-crosthwaite.peter@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>