x86/smp: Initialize cpu_primary_thread_mask late

Marking primary threads in the cpumask during early boot is only correct in
certain configurations, but broken e.g. for the legacy hyperthreading
detection.

This is due to the complete mess in the CPUID evaluation code which
initializes smp_num_siblings only half during early init and fixes it up
later when identify_boot_cpu() is invoked.

So using smp_num_siblings before identify_boot_cpu() leads to incorrect
results.

Fixing the early CPU init code to provide the proper data is a larger scale
surgery as the code has dependencies on data structures which are not
initialized during early boot.

Move the initialization of cpu_primary_thread_mask wich depends on
smp_num_siblings being correct to an early initcall so that it is set up
correctly before SMP bringup.

Fixes: f54d4434 ("x86/apic: Provide cpu_primary_thread mask")
Reported-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/87sfbhlwp9.ffs@tglx