mem-cache: Upgrade Compressor::Multi's stats

Use new style stats API for Compressor::Multi's stats.

Change-Id: Ia0313704cae4e7bd6bc675c71ea75b42a8e542f2
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33377
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2 files changed