Don't call cpu_synchronize_state() from machine init.

This will deadlock when the I/O thread is used, since the
CPU thread is blocked waiting for qemu_system_ready.

The synchronization is unnecessary since this is before
cpu_synchronize_all_post_init().

Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Alexander Graf <agraf@suse.de>