qapi/qom: Change Since entry for AcpiGenericPortProperties to 9.2

qapi/qom: Change Since entry for AcpiGenericPortProperties to 9.2

This feature was only applied during the 9.2 cycle, so reflect
that rather than 9.1.

Reported-by: Daniel P. Berrangé <berrange@redhat.com>
Closes: https://lore.kernel.org/qemu-devel/ZyngEiwmYeZ-DvCy@redhat.com/
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20241107123446.902801-3-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>