misc: Rename Enums namespace as enums

As part of recent decisions regarding namespace
naming conventions, all namespaces will be changed
to snake case.

::Enums became ::enums.

Change-Id: I39b5fb48817ad16abbac92f6254284b37fc90c40
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45420
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
77 files changed