Update Khronos Group copyrights to 2022 (#757)

This PR does not change non-Khronos Group copyrights.

For reference in 2023: I updated the copyrights using the below command and
then manually checked the result -- `cl_extension_template.asciidoc` is the
only file with an oddity in that regard.

```sh
find . \
     -type f \
     ! -path './.git/*' \
     ! -path './generated/*' \
     ! -path './out/*' \
     -exec sed -i {} -e 's/\(Copyright.*20[0-9][0-9]\)-2021/\1-2022/g' \
                     -e 's/\(Copyright.*2021\)/\1-2022/g' \;
```

Author: alycm

CXX_for_OpenCL.txt

@@ -1,4 +1,4 @@
-// Copyright 2019-2021 The Khronos Group. This work is licensed under a
+// Copyright 2019-2022 The Khronos Group. This work is licensed under a
 // Creative Commons Attribution 4.0 International License; see
 // http://creativecommons.org/licenses/by/4.0/
 

Makefile

@@ -1,4 +1,4 @@
-# Copyright (c) 2013-2021 The Khronos Group Inc.
+# Copyright (c) 2013-2022 The Khronos Group Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.

OpenCL_API.txt

@@ -1,4 +1,4 @@
-// Copyright 2017-2021 The Khronos Group. This work is licensed under a
+// Copyright 2017-2022 The Khronos Group. This work is licensed under a
 // Creative Commons Attribution 4.0 International License; see
 // http://creativecommons.org/licenses/by/4.0/
 

OpenCL_C.txt

@@ -1,4 +1,4 @@
-// Copyright 2017-2021 The Khronos Group. This work is licensed under a
+// Copyright 2017-2022 The Khronos Group. This work is licensed under a
 // Creative Commons Attribution 4.0 International License; see
 // http://creativecommons.org/licenses/by/4.0/
 

OpenCL_Cxx.txt

@@ -1,4 +1,4 @@
-// Copyright 2017-2021 The Khronos Group. This work is licensed under a
+// Copyright 2017-2022 The Khronos Group. This work is licensed under a
 // Creative Commons Attribution 4.0 International License; see
 // http://creativecommons.org/licenses/by/4.0/
 

OpenCL_Env.txt

@@ -1,4 +1,4 @@
-// Copyright 2017-2021 The Khronos Group. This work is licensed under a
+// Copyright 2017-2022 The Khronos Group. This work is licensed under a
 // Creative Commons Attribution 4.0 International License; see
 // http://creativecommons.org/licenses/by/4.0/
 

OpenCL_Ext.txt

@@ -1,4 +1,4 @@
-// Copyright 2017-2021 The Khronos Group. This work is licensed under a
+// Copyright 2017-2022 The Khronos Group. This work is licensed under a
 // Creative Commons Attribution 4.0 International License; see
 // http://creativecommons.org/licenses/by/4.0/
 

OpenCL_ICD_Installation.txt

@@ -1,4 +1,4 @@
-// Copyright 2017-2021 The Khronos Group. This work is licensed under a
+// Copyright 2017-2022 The Khronos Group. This work is licensed under a
 // Creative Commons Attribution 4.0 International License; see
 // http://creativecommons.org/licenses/by/4.0/
 

OpenCL_LangExt.txt

@@ -1,4 +1,4 @@
-// Copyright 2019-2021 The Khronos Group. This work is licensed under a
+// Copyright 2019-2022 The Khronos Group. This work is licensed under a
 // Creative Commons Attribution 4.0 International License; see
 // http://creativecommons.org/licenses/by/4.0/