arch-riscv: fix asmtest concurrent issues.

riscv asmtest uses multiprocessing.Pool to run multiple gem5
processes concurrently.

By using gem5 default options, processes will fail because:
 - accessing to the same m5out directory
 - listening too many remote gdb ports at the same time

This will set independent m5out directories and disable remote gdb
ports for asmtest gem5 processes.

Change-Id: Ie4c81232210568cd1945adc2b99eebc019d705b6
Signed-off-by: Xin Ouyang <xin.ouyang@streamcomputing.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22863
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Alec Roelke <alec.roelke@gmail.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

tests/test-progs/asmtest/src/riscv/run-tests.py

@@ -109,6 +109,8 @@ for test in tests:
     test_name = test + '-' + model
     job_names.append(test_name)
     job_cmds.append([gem5_bin,
+                     '-d', 'm5out/' + test_name,
+                     '--listener-mode', 'off',
                      config,
                      '-m', str(args.max_tick),
                      '--cpu-type', model,