qapi/qom: make some QOM properties depend on the build settings

qapi/qom: make some QOM properties depend on the build settings

Some QOM properties are associated with ObjectTypes that already
depend on CONFIG_* switches. So to avoid generating dead code,
let's also make the definition of those properties dependent on
the corresponding CONFIG_*.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-ID: <20240604135931.311709-1-sgarzare@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Make SecretKeyringProperties conditional, too]
Signed-off-by: Markus Armbruster <armbru@redhat.com>