llama : fix llm_build_k_shift to use correct n_rot (#4889)

* llama : fix llm_build_k_shift to use correct n_rot

ggml-ci

* llama : always use hparams.n_rot for ggml_rope_custom

ggml-ci

* convert : fix persimmon conversion to write correct n_rot

common/common.cpp

@@ -1055,6 +1055,9 @@ struct llama_model_params llama_model_params_from_gpt_params(const gpt_params &
 }
 
 static ggml_type kv_cache_type_from_str(const std::string & s) {
+    if (s == "f32") {
+        return GGML_TYPE_F32;
+    }
     if (s == "f16") {
         return GGML_TYPE_F16;
     }