plic-test compile and sim fail

[neelgala]

The compilation and simulation of the Test_PLIC.bsv fails

To reproduce issue: run the makefile in src_Core/PLIC

Compilation Fix:
Axi4_Wr_Data in this line should not have wid field

Simulation Fix (after the above fix): the following line

vrg_irqs [5] <= True;

should be:

vrg_irqs [4] <= True;

Explanation: vrg_irq[i] is connected to source_ip[i+1].