Added testbench for MIPS processor

tests/tests.sv

@@ -3,4 +3,5 @@
 `include "tests/asu_tb.sv"
 `include "tests/instruction_classifier_tb.sv"
 `include "tests/shifter_tb.sv"
-`include "tests/alu_tb.sv"
+`include "tests/alu_tb.sv"
+`include "tests/mips.sv"