util: add update-copyright utility to update copyright on commits

The utility can automatically update copyright for the chosen
organization on all files touched in the selected range of git commits.

Change-Id: I4e1803e53f4530f88fb344f56e08ea29fbfcd41d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35535
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
6 files changed