Fix compilation error on aarch64 by limiting cpuid.h inclusion to x86

[turanzv]

This pull request fixes a compilation error that occurred on aarch64 Linux systems due to the inclusion of cpuid.h, which is specific to Intel x86 architecture.

Problem: The file BaseOT.cpp included cpuid.h when compiled on Linux regardless of the architecture, causing a compile error on aarch64. The cpuid.h header is only valid for x86 (32-bit and 64-bit) systems.

Solution: I updated the preprocessor directive to check if both linux and __x86_64__ are defined, ensuring that cpuid.h is only included on Linux systems running on x86 architectures.

Why: The cpuid.h is only used in systems with AVX support, which is specific to Intel x86 processors. The change prevents compilation issues on aarch64 and other non-x86 architectures.

[CLAassistant]

All committers have signed the CLA.

[mkskeller]

Thank you