hw/arm/sbsa-ref: Check CPU type in machine_run_board_init()

hw/arm/sbsa-ref: Check CPU type in machine_run_board_init()

Set mc->valid_cpu_types so that the user specified CPU type can
be validated in machine_run_board_init(). We needn't to do it
by ourselves.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20231204004726.483558-8-gshan@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>