v3dv: enable multisync in the simulator
Use drmSyncobjSignal to signal out_syncobjs when a CL submission ends in the simulator. In this case, out_syncs can be signal semaphores or fences. With this, we can enable multisync support in the simulator and keep the multisync approach to process fence by submitting a serialized no-op job that adds the fence to its array of out syncobjs, i.e. drm-syncobjs to be signaled in the kernel when a job completes (job post deps).