move arch_init, balloon, cpus, ioport, memory, memory_mapping, qtest.

They are all specific to CONFIG_SOFTMMU.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20200629093504.3228-2-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>