[Feature] Pick npu ops from master to 2.x (#2501)

* merge npu ops from master to 2.x

* BugFix: fix merge bugs

* {[Feature]: add psamask, roipool to 2.x, and fix the SigmoidFocalLoss assert condition

* merge conflicts in ops.md

* [fix]: fix merge bug

tests/test_ops/test_roi_pool.py

@@ -5,7 +5,7 @@ import numpy as np
 import pytest
 import torch
 
-from mmcv.utils import IS_CUDA_AVAILABLE, IS_MLU_AVAILABLE
+from mmcv.utils import IS_CUDA_AVAILABLE, IS_MLU_AVAILABLE, IS_NPU_AVAILABLE
 
 _USING_PARROTS = True
 try:
@@ -86,7 +86,11 @@ class TestRoiPool:
         pytest.param(
             'mlu',
             marks=pytest.mark.skipif(
-                not IS_MLU_AVAILABLE, reason='requires MLU support'))
+                not IS_MLU_AVAILABLE, reason='requires MLU support')),
+        pytest.param(
+            'npu',
+            marks=pytest.mark.skipif(
+                not IS_NPU_AVAILABLE, reason='requires NPU support'))
     ])
     @pytest.mark.parametrize('dtype', [
         torch.float,