Update spike_cosim.cc to be able to build against newer Spikes
Update spike_cosim.cc to be able to build against newer Spikes

This should work with versions ibex-cosim-v0.1 and ibex-cosim-v0.2.

lowRISC/ibex,AmbiML/ibex,AmbiML/ibex,AmbiML/ibex,lowRISC/ibex,lowRISC/ibex,AmbiML/ibex,lowRISC/ibex