acpi: introduce TYPE_ACPI_DEVICE_IF interface

... it will be used to abstract generic ACPI bits from
device that implements ACPI interface.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
acpi: implement ospm_status() method for PIIX4/ICH9_LPC devices

... using TYPE_ACPI_DEVICE_IF interface.
Which provides status reporting of ACPI declared memory devices

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
qmp: add query-acpi-ospm-status command

... to get ACPI OSPM status reported by ACPI devices
via _OST method.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
qmp: add ACPI_DEVICE_OST event handling

emmits event when ACPI OSPM evaluates _OST method
of ACPI device.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>