Disable cpuinfo for ARM64EC builds. (#25831)
### Description
<!-- Describe your changes. -->
Disable cpuinfo for ARM64EC builds. There's an error when linking to
cpuinfo built for ARM64EC when using `--use_vckpg`.
This issue was exposed by a recent change (#25228) but cpuinfo was
actually not being used before for ARM64EC. The macros here don't
properly account for ARM64EC:
https://github.com/microsoft/onnxruntime/blob/e6d3e085cb0bb96da7c3458b97316ecca234b37a/onnxruntime/core/common/cpuid_arch_definition.h#L8-L14
### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->
Fix a packaging pipeline failure. Revert to the old behavior of not
calling cpuinfo from the CPUIDInfo ctor for ARM64EC.
This PR is just a workaround. The cpuinfo link issue needs more
investigation.
