ggml-cpu: Add CPU backend support for KleidiAI library

include/llama.h

@@ -304,6 +304,8 @@ extern "C" {
         bool use_mmap;      // use mmap if possible
         bool use_mlock;     // force system to keep model in RAM
         bool check_tensors; // validate model tensor data
+
+        int n_threads;
     };
 
     // NOTE: changing the default values of parameters marked as [EXPERIMENTAL] may cause crashes or incorrect results in certain configurations