feat: support for cross-device row split (#1735)

src/upscaler.cpp

@@ -46,6 +46,7 @@ bool UpscalerGGML::load_from_file(const std::string& esrgan_path,
     std::string error;
     if (!backend_manager.init(backend_spec.c_str(),
                               params_backend_spec.c_str(),
+                              /*split_mode_spec=*/nullptr,
                               &error)) {
         LOG_ERROR("upscaler backend config failed: %s", error.c_str());
         return false;