qdev: all globals are now user-provided

qdev: all globals are now user-provided

All globals are now either provided via -global or through -cpu
features (CPU features are implemented by registering globals).

If the global isn't being used, it should warn in either case.

We can thus consider that all global_props are "user-provided"
globals. No need to track this per-globals anymore.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com>