QOM propertyify the .may-overlap and .priority fields. The setters
will re-add the memory as a subregion if needed (i.e. the values change
when the memory region is already contained).
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
[Remove setters. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>