Issue Running riscv_virt_lmac2_demo

When running riscv_virt_lmac2_demo, I encounter messages related to riscv_virt_lmac2_demo. 

```
Info: (I702) default timescale unit used for tracing: 1 ps (trace.vcd)
```

I have explicitly set VM_TRACE=0 in the config.mk during compilation, but the issue persists. 

How can I disable the tracing signal feature? The reason for disabling it is that the startup time is significantly slow.