OSS cleanup on the host_tool

Update the encoding generator to support the OSS header

Change-Id: Ibf993db8218f9fda51218b75986b0a94d52ccba0

crt/kelvin_intrinsics.h

diff --git a/crt/kelvin_intrinsics.h b/crt/kelvin_intrinsics.h
index c20e21d..6fa3057 100644
--- a/crt/kelvin_intrinsics.h
+++ b/crt/kelvin_intrinsics.h
@@ -1,18 +1,17 @@
-/*
- * Copyright 2023 Google LLC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
 // clang-format off
 
 // Kelvin instruction intrinsics

host_tools/encoding_main.cc

diff --git a/host_tools/encoding_main.cc b/host_tools/encoding_main.cc
index dcbb91e..ee154b2 100644
--- a/host_tools/encoding_main.cc
+++ b/host_tools/encoding_main.cc
@@ -91,14 +91,25 @@
 
 void Header() {
   // OSS header.
+  const std::string oss_header = R"(// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// clang-format off
+
+)";
   for (auto fp : {fc_, fh_, fi_}) {
-    fprintf(fp,
-            "// Copyright 2023 Google LLC\n"
-            "// Licensed under the Apache License, Version 2.0, see LICENSE "
-            "for details.\n"
-            "// SPDX-License-Identifier: Apache-2.0\n"
-            "//\n"
-            "// clang-format off\n\n");
+    fprintf(fp, oss_header.c_str());
   }
   fprintf(fh_,
           "#ifndef PATCHES_KELVIN_KELVIN_OPC_H_\n"