[Feature Request] Add amx detection in cpuinfo

[mingfeima]

This proposal is to add amx detection in cpuinfo, amx refers to Intel® Advanced Matrix Extensions (Intel® AMX): https://www.intel.com/content/www/us/en/products/docs/accelerator-engines/advanced-matrix-extensions/overview.html

something like:

cpuinfo_has_x86_amxbf16()
cpuinfo_has_x86_amxint8()

once this is settled, we can also switch the check from torch/aten to cpuinfo in convolution. Right now it is checked inside oneDNN via: https://github.com/pytorch/pytorch/blob/main/aten/src/ATen/native/mkldnn/Utils.h#L99