Enable SQRT operator for the nGraph Bridge (#17549)

* Enable sqrt operator for the nGraph Bridge.

test=develop

* Update activation_op.h

paddle/fluid/operators/ngraph/ops/activation_op.h

@@ -113,5 +113,6 @@ void BuildTanhGradNode(
 REGISTER_NG_OP(gelu, BuildGeluNode);
 REGISTER_NG_OP(gelu_grad, BuildGeluGradNode);
 REGISTER_NG_OP(relu_grad, BuildReluGradNode);
+REGISTER_NG_OP(sqrt, BuildUnaryNode<ngraph::op::Sqrt>);
 REGISTER_NG_OP(square, BuildSquareNode);
 REGISTER_NG_OP(tanh_grad, BuildTanhGradNode);

python/paddle/fluid/tests/unittests/ngraph/test_activation_ngraph_op.py

@@ -18,7 +18,7 @@ import unittest
 import numpy as np
 import paddle.fluid.core as core
 from paddle.fluid.tests.unittests.op_test import OpTest
-from paddle.fluid.tests.unittests.test_activation_op import TestAbs, TestGelu, TestSigmoid, TestSquare, TestRelu, TestTanh
+from paddle.fluid.tests.unittests.test_activation_op import TestAbs, TestGelu, TestSigmoid, TestSqrt, TestSquare, TestRelu, TestTanh
 
 
 class TestNGRAPHReluDim4(TestRelu):