Instead of passing the CPU index and resolving it,
use a QOM link to directly pass the CPU.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20231030083706.63685-1-philmd@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>