ggml: ggml-cpu: force-no-lto-for-cpu-feats (llama/19609)

ggml: ggml-cpu: force-no-lto-for-cpu-feats (llama/19609)

When LTO enabled in build environments it forces all builds to have LTO
in place. But feature detection logic is fragile, and causing Illegal
instruction errors with lto. This disables LTO for the feature
detection code to prevent cross-module optimization from inlining
architecture-specific instructions into the score function. Without this,
LTO can cause SIGILL when loading backends on older CPUs (e.g., loading
power10 backend on power9 crashes before feature check runs).