[npu] change device to accelerator api (#5239)

* update accelerator

* fix timer

* fix amp

* update

* fix

* update bug

* add error raise

* fix autocast

* fix set device

* remove doc accelerator

* update doc

* update doc

* update doc

* use nullcontext

* update cpu

* update null context

* change time limit for example

* udpate

* update

* update

* update

* [npu] polish accelerator code

---------

Co-authored-by: Xuanlei Zhao <xuanlei.zhao@gmail.com>
Co-authored-by: zxl <43881818+oahzxl@users.noreply.github.com>

tests/test_zero/test_gemini/test_optim.py

@@ -5,11 +5,11 @@ from torch.nn.parallel import DistributedDataParallel as DDP
 from torch.testing import assert_close
 
 import colossalai
+from colossalai.accelerator import get_accelerator
 from colossalai.legacy.amp import convert_to_apex_amp
 from colossalai.nn.optimizer import HybridAdam
 from colossalai.testing import DummyDataloader, parameterize, rerun_if_address_is_in_use, spawn
 from colossalai.utils import set_seed
-from colossalai.utils.device import get_current_device
 from colossalai.zero import GeminiDDP, GeminiOptimizer
 from colossalai.zero.gemini.chunk import search_chunk_configuration
 from tests.kit.model_zoo import model_zoo, run_fwd_bwd
@@ -150,7 +150,7 @@ def exam_tiny_example(placement_config, model_name: str, mixed_precision: torch.
 
     model = GeminiDDP(
         model,
-        chunk_init_device=get_current_device(),
+        chunk_init_device=get_accelerator().get_current_device(),
         search_range_m=1,
         pin_memory=True,
         mixed_precision=mixed_precision,