Update regress/ICache.fir with fixed mport

Update the ICache.fir regression test from Rocket Chip.  This was built
using Chisel3 3.4.3 with an unmerged fix that includes a wire to avoid
letting an mport escape the when scope in which it is defined.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@sifive.com>