chore: make yuzu REUSE compliant

[REUSE] is a specification that aims at making file copyright
information consistent, so that it can be both human and machine
readable. It basically requires that all files have a header containing
copyright and licensing information. When this isn't possible, like
when dealing with binary assets, generated files or embedded third-party
dependencies, it is permitted to insert copyright information in the
`.reuse/dep5` file.

Oh, and it also requires that all the licenses used in the project are
present in the `LICENSES` folder, that's why the diff is so huge.
This can be done automatically with `reuse download --all`.

The `reuse` tool also contains a handy subcommand that analyzes the
project and tells whether or not the project is (still) compliant,
`reuse lint`.

Following REUSE has a few advantages over the current approach:

- Copyright information is easy to access for users / downstream
- Files like `dist/license.md` do not need to exist anymore, as
  `.reuse/dep5` is used instead
- `reuse lint` makes it easy to ensure that copyright information of
  files like binary assets / images is always accurate and up to date

To add copyright information of files that didn't have it I looked up
who committed what and when, for each file. As yuzu contributors do not
have to sign a CLA or similar I couldn't assume that copyright ownership
was of the "yuzu Emulator Project", so I used the name and/or email of
the commit author instead.

[REUSE]: https://reuse.software

Follow-up to b2eb10382941bef0914f4a0a4685b9033440aa9f

8 files changed, 23 insertions, 0 deletions

diff --git a/CMakeModules/CopyYuzuFFmpegDeps.cmake b/CMakeModules/CopyYuzuFFmpegDeps.cmake
index f5ab2806c0..c6231737e3 100644
--- a/CMakeModules/CopyYuzuFFmpegDeps.cmake
+++ b/CMakeModules/CopyYuzuFFmpegDeps.cmake
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2020 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 function(copy_yuzu_FFmpeg_deps target_dir)
     include(WindowsCopyFiles)
     set(DLL_DEST "${CMAKE_BINARY_DIR}/bin/$<CONFIG>/")
diff --git a/CMakeModules/CopyYuzuQt5Deps.cmake b/CMakeModules/CopyYuzuQt5Deps.cmake
index 6c5044caa7..a353ddbb77 100644
--- a/CMakeModules/CopyYuzuQt5Deps.cmake
+++ b/CMakeModules/CopyYuzuQt5Deps.cmake
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2016 Citra Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 function(copy_yuzu_Qt5_deps target_dir)
     include(WindowsCopyFiles)
     if (MSVC)
diff --git a/CMakeModules/CopyYuzuSDLDeps.cmake b/CMakeModules/CopyYuzuSDLDeps.cmake
index 5963684f45..7ffdd8a1d5 100644
--- a/CMakeModules/CopyYuzuSDLDeps.cmake
+++ b/CMakeModules/CopyYuzuSDLDeps.cmake
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2016 Citra Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 function(copy_yuzu_SDL_deps target_dir)
     include(WindowsCopyFiles)
     set(DLL_DEST "${CMAKE_BINARY_DIR}/bin/$<CONFIG>/")
diff --git a/CMakeModules/DownloadExternals.cmake b/CMakeModules/DownloadExternals.cmake
index 4c4dec5ff3..8fe5ba48df 100644
--- a/CMakeModules/DownloadExternals.cmake
+++ b/CMakeModules/DownloadExternals.cmake
@@ -1,3 +1,5 @@
+# SPDX-FileCopyrightText: 2017 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 # This function downloads a binary library package from our external repo.
 # Params:
diff --git a/CMakeModules/GenerateSCMRev.cmake b/CMakeModules/GenerateSCMRev.cmake
index c7da2b91d6..0e4bd121c4 100644
--- a/CMakeModules/GenerateSCMRev.cmake
+++ b/CMakeModules/GenerateSCMRev.cmake
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 # Gets a UTC timstamp and sets the provided variable to it
 function(get_timestamp _var)
     string(TIMESTAMP timestamp UTC)
diff --git a/CMakeModules/MSVCCache.cmake b/CMakeModules/MSVCCache.cmake
index 8848e35ead..ba0d22d9ee 100644
--- a/CMakeModules/MSVCCache.cmake
+++ b/CMakeModules/MSVCCache.cmake
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2022 yuzu Emulator Project

+# SPDX-License-Identifier: GPL-3.0-or-later

+

 # buildcache wrapper

 OPTION(USE_CCACHE "Use buildcache for compilation" OFF)

 IF(USE_CCACHE)

diff --git a/CMakeModules/MinGWClangCross.cmake b/CMakeModules/MinGWClangCross.cmake
index ccf4dbf405..286a59a7ad 100644
--- a/CMakeModules/MinGWClangCross.cmake
+++ b/CMakeModules/MinGWClangCross.cmake
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2022 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-3.0-or-later
+
 set(MINGW_PREFIX                /usr/x86_64-w64-mingw32/)
 set(CMAKE_SYSTEM_NAME           Windows)
 set(CMAKE_SYSTEM_PROCESSOR      x86_64)
diff --git a/CMakeModules/MinGWCross.cmake b/CMakeModules/MinGWCross.cmake
index b268e72d83..61464f7dae 100644
--- a/CMakeModules/MinGWCross.cmake
+++ b/CMakeModules/MinGWCross.cmake
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2018 tech4me <guiwanglong@gmail.com>
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 set(MINGW_PREFIX   /usr/x86_64-w64-mingw32/)
 set(CMAKE_SYSTEM_NAME               Windows)
 set(CMAKE_SYSTEM_PROCESSOR           x86_64)