Do not require the whole option machinery to handle keyval, as it is
used by QAPI alone, without the option API. And match the associated
unit name.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220420132624.2439741-24-marcandre.lureau@redhat.com>