[CMAKE] Fix warnings in CPU cmake code

[ilya-lavrenov]

Details:

Fix the following warnings

CMake Warning at cmake/developer_package/compile_flags/os_flags.cmake:252 (message):
  fp16 is not supported by architecture x86_64
Call Stack (most recent call first):
  cmake/developer_package/cross_compile/cross_compiled_func.cmake:29 (ov_arm_neon_fp16_optimization_flags)
  cmake/developer_package/OpenVINODeveloperScriptsConfig.cmake:261 (include)
  CMakeLists.txt:49 (find_package)


CMake Warning at cmake/developer_package/compile_flags/os_flags.cmake:294 (message):
  SVE is not supported by architecture x86_64
Call Stack (most recent call first):
  cmake/developer_package/cross_compile/cross_compiled_func.cmake:30 (ov_arm_sve_optimization_flags)
  cmake/developer_package/OpenVINODeveloperScriptsConfig.cmake:261 (include)
  CMakeLists.txt:49 (find_package)

[dmitry-gorokhov]

With that change in case ENABLE_NEON_FP16=OFF or ENABLE_SVE=OFF dispatch function will still look like:

    if (with_cpu_neon_fp16()) {
        return NEON_FP16::attn_softmax(a, a_dst, scale, alibi, attn_mask, causal_mask, select_nfltmax_at_0, len, total_size, precision, attn_mask_prec, dst_precision);
    }
    if (with_cpu_sve()) {
        return SVE::attn_softmax(a, a_dst, scale, alibi, attn_mask, causal_mask, select_nfltmax_at_0, len, total_size, precision, attn_mask_prec, dst_precision);
    }
    if (true) {
        return ANY::attn_softmax(a, a_dst, scale, alibi, attn_mask, causal_mask, select_nfltmax_at_0, len, total_size, precision, attn_mask_prec, dst_precision);
    }

The only difference is that NEON_FP16::attn_softmax is compiled w/o -march=armv8.2-a+fp16.