[ROCm][bugfix] scpecilative decoding worker class (#11035)

Signed-off-by: Gregory Shtrasberg <Gregory.Shtrasberg@amd.com>

vllm/platforms/rocm.py

@@ -93,6 +93,8 @@ class RocmPlatform(Platform):
             elif vllm_config.speculative_config:
                 parallel_config.worker_cls = \
                     "vllm.spec_decode.spec_decode_worker.create_spec_worker"
+                parallel_config.sd_worker_cls = \
+                    "vllm.worker.worker.Worker"
             else:
                 parallel_config.worker_cls = "vllm.worker.worker.Worker"