mark comment for improvement in the future

Co-authored-by: Georgi Gerganov <[email protected]>

ggml-sycl.h

@@ -28,6 +28,9 @@ GGML_API GGML_CALL int   ggml_backend_sycl_get_device_count();
 GGML_API GGML_CALL ggml_backend_buffer_type_t ggml_backend_sycl_split_buffer_type(const float * tensor_split);
 GGML_API GGML_CALL void ggml_backend_sycl_get_device_memory(int device, size_t *free, size_t *total);
 GGML_API GGML_CALL int ggml_backend_sycl_get_device_index(int device_id);
+
+// TODO: these are temporary
+//       ref: https://github.com/ggerganov/llama.cpp/pull/6022#issuecomment-1992615670
 GGML_API GGML_CALL int ggml_backend_sycl_get_device_id(int device_index);
 GGML_API GGML_CALL void ggml_backend_sycl_set_single_device_mode(int main_gpu_id);
 GGML_API GGML_CALL void ggml_backend_sycl_set_mul_device_mode();