pc: ich9 lpc: make it work with global/compat properties

pc: ich9 lpc: make it work with global/compat properties

Propeties of object should be available after its instances_init()
callback is finished and not added in PCIDeviceClass.init which is
roughly corresponds to realize() method.
Moving properties adding into instances_init will fix missing
property error when global/compat property mechanism is used.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>