move the call for sysemu specifically in machine_run_board_init,
mirror the calling sequence for user mode too.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20210322132800.7470-23-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>