util-docker: Add gpu-fs to docker-compose.yaml
util-docker: Add gpu-fs to docker-compose.yaml

Though https://gem5-review.googlesource.com/c/public/gem5/+/59051 added
the gpu-fs image, it needs added to the docker-compose.yaml file to be
automatically build and pushed to our docker image repository.

With this patch a user can execute `docker-compose build gpu-fs` to
build this image locally.

Change-Id: Iacc768d3d1b7fccb8867e8c788012c292216cb02
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/59349
Reviewed-by: Jason Lowe-Power <92de577f37050ad05b60626d2f17913f40dcb1a2@gmail.com>
Maintainer: Jason Lowe-Power <92de577f37050ad05b60626d2f17913f40dcb1a2@gmail.com>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5