[Misc] Refactor additional_config (#1029)

More and more config options are added to additional_config. This PR
provide a new AscendConfig to manage these config options by an easier
way to make code cleaner and readable.

 This PR also added the `additional_config` doc for users.

Added the test_ascend_config.py to make sure the new AscendConfig works
as expect.

TODO: Add e2e test with torchair and deepseek once the CI resource is
available.

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>

vllm_ascend/worker/worker.py

@@ -47,6 +47,7 @@ from vllm.worker.model_runner_base import ModelRunnerBase
 from vllm.worker.worker_base import (LocalOrDistributedWorkerBase, WorkerBase,
                                      WorkerInput)
 
+from vllm_ascend.ascend_config import init_ascend_config
 from vllm_ascend.device_allocator.camem import CaMemAllocator
 from vllm_ascend.distributed.parallel_state import init_ascend_model_parallel
 from vllm_ascend.platform import NPUPlatform
@@ -75,6 +76,9 @@ class NPUWorker(LocalOrDistributedWorkerBase):
         # Register ops when worker init.
         from vllm_ascend import ops  # noqa: F401
 
+        # init ascend config
+        init_ascend_config(vllm_config)
+
         WorkerBase.__init__(self, vllm_config=vllm_config)
         # Try to import mindie_turbo to accelerate vLLM inference.
         try_register_lib(