pcihp: remove unused AcpiPciHpPciStatus.device_present field

Remove now unused 'device_present' field wich was obsoleted by
patch "pcihp: reduce number of device check events"

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
