ppc/e500: Use start-powered-off CPUState property

ppc/e500: Use start-powered-off CPUState property

Instead of setting CPUState::halted to 1 in ppce500_cpu_reset_sec(), use
the start-powered-off property which makes cpu_common_reset() initialize it
to 1 in common code.

Also change creation of CPU object from cpu_create() to object_new() and
qdev_realize_and_unref() because cpu_create() realizes the CPU and it's not
possible to set a property after the object is realized.

Signed-off-by: Thiago Jung Bauermann <[email protected]>
Message-Id: <20200826055535[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Signed-off-by: David Gibson <[email protected]>