Just use the same ID for all outstanding requests such that all requests
are in-order.
Previously we were working fine with requests serialised; requests
are now fully pipelined and out-of-order.
This change should roll back to in-order, but still pipelined.
This only affects the top-level used in the GFE (vcu118).
This design is working on the DE10 setup, so the issue is not
believed fundamental with CoreW.
f86ea0203d