tests,gpu-compute,mem-ruby: Add GPU Ruby random test
tests,gpu-compute,mem-ruby: Add GPU Ruby random test

This adds the GPU protocol random tester to the quick/Kokoro tests. The
input has been sized to take around 20 seconds and provides good
coverage for the coherence protocol.

This test can be run with the following:

```
cd tests
./main.py run -j`nproc` gem5/gpu
```

Change-Id: I08d199f0de8cca985f992b7f39b5f82e4218c82d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/58270
Maintainer: Bobby Bruce <b9dba908ffb6c6d8ffe449cc88b3709c13c485c2@ucdavis.edu>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Reviewed-by: Matt Sinclair <d2406197fb1bedd1e23c70c50c510ff0e9ab0f5b@gmail.com>
Maintainer: Matt Sinclair <d2406197fb1bedd1e23c70c50c510ff0e9ab0f5b@gmail.com>

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