base: Update the version to v21.0.1.0

Change-Id: Ieffc677d2daf0aadf82ede94d989e4b9a5bd17be
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/47079
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
2 files changed