hw/arm/aspeed: Move AspeedSoCState::a7mpcore to Aspeed2600SoCState
The v7-A cluster is specific to the Aspeed 2600 series,
remove it from the common AspeedSoCState.
The ARM cores belong to the MP cluster, but the array
is currently used by TYPE_ASPEED2600_SOC. We'll clean
that soon, but for now keep it in Aspeed2600SoCState.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Cédric Le Goater <clg@kaod.org>