Change in coreboot[master]: cpu/intel/sandybridge: Add `hyper_threading` option

[Nico Huber (Code Review)]

Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/29669 )

Change subject: cpu/intel/sandybridge: Add `hyper_threading` option
......................................................................

Patch Set 4:
> Patch Set 4:
>
> The ACPI problems were caused by `get_cores_per_package()` function. It was using CPUID 0Bh function, that returns number of logical processes of requested level to EBX. According to Intel's manual, this value is not changed if HT was disabled.
>
> int totalcores = dev_count_cpu(); // this was 2
> int cores_per_package = get_cores_per_package(); // this was 4, when it had to be 2
> int numcpus = totalcores/cores_per_package; // so this was 0
>
> I updated the `get_cores_per_package` function, now it uses MSR 0x35 instead of CPUID. I hope that doesn't break anything.

AFAIK, 206ax only supports uni-processor systems anyway. I think we can
simply drop the `numcpus` loop.