Improve SPDX identifier coverage (#716)

* Change MIT license texts to SPDX-License-Identifier

SPDX-License-Identifier is much easier to understand and grep than
license text so use that instead.

* Change GPL exception license texts to SPDX-License-Identifier

SPDX-License-Identifier is much easier to understand and grep than
license text so use that instead.

* Change misc license texts to SPDX-License-Identifier

There are some external code in repo which are not licenses as most of
the stuff in this repo. We still want every file to have SPDX identifier
to easily grep licenses.

* Add currently used license files

Even though Bacnet-Stack is using SPDX identifiers we still need to give
those license files with source. For this reason add all license files
to license/ folder.

SPDX has also files which would make same thing but this is style which
example Linux kernel is using and it is quite clear so I choose that one
for now.

I choosed not yet bring CC-PDDC as that is not right license for those
files.

---------

Co-authored-by: Kari Argillander <kari.argillander@fidelix.com>

test/ztest/include/zephyr/fff.h

@@ -1,28 +1,8 @@
 /*
-LICENSE
-
-The MIT License (MIT)
-
-Copyright (c) 2010 Michael Long
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
-*/
+ * Copyright (c) 2010 Michael Long
+ *
+ * SPDX-License-Identifier: MIT
+ */
 #ifndef FAKE_FUNCTIONS
 #define FAKE_FUNCTIONS
 

test/ztest/include/zephyr/test_utils.h

@@ -3,30 +3,7 @@
 /*
  *  Copyright (C) 2015 by Intel Corporation, All Rights Reserved.
  *
- *  Redistribution and use in source and binary forms, with or without
- *  modification, are permitted provided that the following conditions are met:
- *
- *    - Redistributions of source code must retain the above copyright notice,
- *     this list of conditions and the following disclaimer.
- *
- *    - Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- *    - Neither the name of Intel Corporation nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- *
- *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- *  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
- *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- *  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- *  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- *  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- *  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *  SPDX-License-Identifier: BSD-3-Clause
  */
 
 #ifndef __TEST_UTILS_H__