licenses: Add SPDX headers to the git commit hook scripts

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

utils/hooks/post-commit

@@ -1,5 +1,7 @@
 #!/bin/sh
 
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 # Execute the checkstyle script after committing any code. This allows the
 # commit to succeed, but ensures that the developer is aware of any potential
 # issues immediately, and can resolve them and fix rapidly with:

utils/hooks/pre-commit

@@ -1,5 +1,7 @@
 #!/bin/sh
 
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 # Execute the checkstyle script before committing any code. This will fail the
 # commit in case of style issues, ensuring that the developer will notice them.
 # The pre-commit hook can be bypassed with git commit -n to ignore selective

utils/hooks/pre-push

@@ -1,5 +1,7 @@
 #!/bin/sh
 
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 # A hook script to prevent pushing unsuitable commits to the master branch.
 # Unsuitable commits are commits that contain a local changelog below a '---'
 # line. The criteria may get extended later.