i386/cpu: Consolidate die-id validity in smp context

i386/cpu: Consolidate die-id validity in smp context

The field die_id (default as 0) and has_die_id are introduced to X86CPU.
Following the legacy smp check rules, the die_id validity is added to
the same contexts as leagcy smp variables such as hmp_hotpluggable_cpus(),
machine_set_cpu_numa_node(), cpu_slot_to_string() and pc_cpu_pre_plug().

Acked-by: Dr. David Alan Gilbert <[email protected]>
Signed-off-by: Like Xu <[email protected]>
Message-Id: <20190612084104[email protected]>
Reviewed-by: Eduardo Habkost <[email protected]>
Signed-off-by: Eduardo Habkost <[email protected]>