risc-v tests are not passing

[Hossein Askari]

RISC-V tests are not passing. At the end of each risc-v test, we should see OK\n or ERR\n in register a0-a3. Right now, these registers are not modified throughout the test, look at the waveforms:

Also, the simulation output for running add.hex is as below where RISC-V TEST Result is showing wrong output:

1000000: 00058a63 0 pc:8000000c -- opcode:1100011 -- func:0 alt:0 left:8000000c imm:00000014 pend:80000020 d_addr:0020 d_data:00ffff81 trap:0
1000000: 00b62023 0 pc:80000010 -- opcode:0100011 -- func:0 alt:0 left:10000000 imm:00000000 pend:10000000 d_addr:0000 d_data:02e00593 trap:0
1000000: 00150513 0 pc:80000014 -- opcode:0010011 -- func:0 alt:0 left:000000a9 imm:00000001 pend:000000aa d_addr:00aa d_data:ffffff83 trap:0
1000000: ff1ff06f 0 pc:80000018 -- opcode:1101111 -- func:0 alt:0 left:80000018 imm:fffffff0 pend:80000008 d_addr:0008 d_data:0000ffff trap:0
1000000: 00050583 0 pc:80000008 -- opcode:0000011 -- func:0 alt:0 left:000000aa imm:00000000 pend:000000aa d_addr:00aa d_data:00050583 trap:0
1000000: 00058a63 0 pc:8000000c -- opcode:1100011 -- func:0 alt:0 left:8000000c imm:00000014 pend:80000020 d_addr:0020 d_data:0000ffff trap:0
no more work 136
RISC-V TEST Result:    ?????       
../src/twitchcore_0/verification/testbench.sv:81: $finish called at 50000 (1s)