9432169 kernel-rebase/c9s: Add prepdistgit stage to assist in the release process

Authored and Committed by ngompa 2 years ago
    kernel-rebase/c9s: Add prepdistgit stage to assist in the release process
    
    This new stage does the work to prepare the Dist-Git repository to commit
    the update. It does not actually upload sources or commit to the repo,
    but it does simplify the process to actually prepare for doing that.