Interconnect test fails when input stream fanout to all tracks.

[kongty]

Interconnect fifo test fails when inputs are fanned out.
https://github.com/StanfordAHA/garnet/tree/5ce15fac5f403c6f28c596df0a042812a44ccbd5

If we are not going to used gated mux, we need to config all 1bit control inputs. (not only flush, but also wr_en, rd_en, chain_in, etc)
Or, we can connect input stream to just track 0.

[Kuree]

See #311