Fix CPU_INTEL flag error on windows (#30564)
Summary:
${CMAKE_HOST_SYSTEM_PROCESSOR} get processor name by `uname -p` on linux and `%PROCESSOR_ARCHITECTURE%` on windows
1. %PROCESSOR_ARCHITECTURE% has value in (AMD64|IA64|ARM64) for 64-bit processor, and (x86) for 32-bit processor
2. `uname -p` has value like "(x86_64|i[3-6]+86)"
We cannot tell intel cpu from other cpus by ${CMAKE_HOST_SYSTEM_PROCESSOR}. It is the architecture, not provider.
i. e. Intel CPU i7-9700K CPU on windows get "AMD64"
reference:
[MSDN](https://docs.microsoft.com/zh-cn/windows/win32/winprog64/wow64-implementation-details?redirectedfrom=MSDN)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/30564
Differential Revision: D18763031
Pulled By: ezyang
fbshipit-source-id: 11ae20e66b4b89bde1dcf4df6177606a3374c671
