arch, base, sim: Replace Copy(String)?(In|Out) with equivalent code.

arch, base, sim: Replace Copy(String)?(In|Out) with equivalent code.

This expands those functions into code which extracts the virt proxy
and then uses the appropriate method on it. This has two benefits.
First, the Copy* functions where mostly redundant wrappers around the
methods the proxy port already had. Second, using them forced a
particular port which might not actually be what the user wanted.

Change-Id: I62084631dd080061e3c74997125164f40da2d77c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18575
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>