Add Apache license/Google LLC copyright on configuration files

LwIP headers and adaptation C files have been created as a part of the
device adaptation layer, and were tagged with an incorrect license
header upon committing to OpenWeave.  This commit addresses the issue

Author: robszewczyk

src/lwip/freertos/arch/sys_arch.h

@@ -1,15 +1,21 @@
 /*
- *
- *    Copyright (c) 2015 Nest Labs, Inc.
+ *    Copyright (c) 2018-2019 Google LLC.
  *    All rights reserved.
  *
- *    This document is the property of Nest. It is considered
- *    confidential and proprietary information.
+ *    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
  *
- *    This document may not be reproduced or transmitted in any form,
- *    in whole or in part, without the express written permission of
- *    Nest.
+ *        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.
+ */
+
+/*
  *    Description:
  *      LwIP sys_arch definitions for use with FreeRTOS.
  *

src/lwip/freertos/sys_arch.c

@@ -1,14 +1,21 @@
 /*
- *
- *    Copyright (c) 2015 Nest Labs, Inc.
+ *    Copyright (c) 2018-2019 Google LLC.
  *    All rights reserved.
  *
- *    This document is the property of Nest. It is considered
- *    confidential and proprietary information.
+ *    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
  *
- *    This document may not be reproduced or transmitted in any form,
- *    in whole or in part, without the express written permission of
- *    Nest.
+ *    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.
+ */
+
+/*
  *
  *    Description:
  *      LwIP sys_arch definitions for use with FreeRTOS.

src/lwip/nrf5/arch/cc.h

@@ -1,14 +1,21 @@
 /*
- *
- *    Copyright (c) 2012 Nest Labs, Inc.
+ *    Copyright (c) 2018-2019 Google LLC.
  *    All rights reserved.
  *
- *    This document is the property of Nest. It is considered
- *    confidential and proprietary information.
+ *    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
  *
- *    This document may not be reproduced or transmitted in any form,
- *    in whole or in part, without the express written permission of
- *    Nest.
+ *    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.
+ */
+
+/*
  *
  *    Description:
  *      This file defines processor-architecture- and toolchain-

src/lwip/nrf5/arch/perf.h

@@ -1,14 +1,21 @@
 /*
- *
- *    Copyright (c) 2012 Nest Labs, Inc.
+ *    Copyright (c) 2018-2019 Google LLC.
  *    All rights reserved.
  *
- *    This document is the property of Nest. It is considered
- *    confidential and proprietary information.
+ *    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
  *
- *    This document may not be reproduced or transmitted in any form,
- *    in whole or in part, without the express written permission of
- *    Nest.
+ *    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.
+ */
+
+/*
  *
  *    Description:
  *      This file defines processor-architecture-specific constants,