misc: Re-remove Authors lines from source files.

misc: Re-remove Authors lines from source files.

These were universally removed a while ago, but a bunch have crept back
in. Remove them.

Change-Id: I3cb5b9f40c9c19aafb5e39a51d1baeae60a591c0
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40335
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Maintainer: Gabe Black <gabe.black@gmail.com>