The 'gen_id' argument refers to a QOM object able to produce
data consumable by the fw_cfg device. The producer object must
implement the FW_CFG_DATA_GENERATOR interface.

Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200623172726.21040-4-philmd@redhat.com>