POWER : Fix build failure due to unsupported cpuinfo on ppc64le (#27120)
Description
Conditionally disable linking of cpuinfo for
onnxruntime_runtime_path_test_shared_library on targets, where cpuinfo
is not supported.
Motivation and Context
Recent changes enabling onnxruntime_autoep_test and related shared
library tests on non-Windows platforms exposed a transitive dependency
issue. cpuinfo was being linked unconditionally on Linux, leading to
linker failures on ppc64le (cannot find -lcpuinfo).
Solution
Add CPUINFO_SUPPORTED guards to exclude cpuinfo from the link list while
preserving existing behavior.