x86/S3: don't lose previously collected CPU data (AMD extra)

smp_store_cpu_info() doesn't call identify_cpu() again during S3 resume,
hence it is wrong to zap APs' data while bringing them down (and we're
not just parking them there) during suspend.

Fixes: 7126b7f806 ("x86/CPU: re-work populating of cpu_data[]")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>

xen/arch/x86/smpboot.c

@@ -982,7 +982,8 @@ static void cpu_smpboot_free(unsigned int cpu, bool remove)
 
     if ( remove )
     {
-        reset_cpuinfo(&c[cpu], false);
+        if ( system_state != SYS_STATE_suspend )
+            reset_cpuinfo(&c[cpu], false);
 
         FREE_CPUMASK_VAR(per_cpu(cpu_sibling_mask, cpu));
         FREE_CPUMASK_VAR(per_cpu(cpu_core_mask, cpu));