Revert "Enable SQRT operator for the nGraph Bridge"

[luotao1]

Reverts #17549

[22:16:34]	In file included from /paddle/build/paddle/fluid/operators/ngraph/ngraph_ops.h:12:0,
[22:16:34]	                 from /paddle/paddle/fluid/operators/ngraph/ngraph_bridge.cc:23:
[22:16:34]	/paddle/paddle/fluid/operators/ngraph/ops/activation_op.h: In constructor 'ng_sqrt_converter::ng_sqrt_converter()':
[22:16:34]	/paddle/paddle/fluid/operators/ngraph/ops/activation_op.h:116:101: error: 'BuildUnaryNode' is not a member of 'paddle::operators::ngraphs'
[22:16:34]	/paddle/paddle/fluid/operators/ngraph/ops/activation_op.h:116:160: error: expected primary-expression before '>' token
[22:16:34]	/paddle/paddle/fluid/operators/ngraph/ops/activation_op.h:116:161: error: expected primary-expression before ',' token
[22:16:34]	make[2]: *** [paddle/fluid/operators/ngraph/CMakeFiles/ngraph_bridge.dir/ngraph_bridge.cc.o] Error 1
[22:16:34]	paddle/fluid/operators/ngraph/CMakeFiles/ngraph_bridge.dir/build.make:62: recipe for target 'paddle/fluid/operators/ngraph/CMakeFiles/ngraph_bridge.dir/ngraph_bridge.cc.o' failed
[22:16:34]	make[1]: *** [paddle/fluid/operators/ngraph/CMakeFiles/ngraph_bridge.dir/all] Error 2
[22:16:34]	CMakeFiles/Makefile2:62623: recipe for target 'paddle/fluid/operators/ngraph/CMakeFiles/ngraph_bridge.dir/all' failed
[22:16:34]	make[1]: *** Waiting for unfinished jobs....
[22:16:35]	

http://ci.paddlepaddle.org/viewLog.html?buildId=105021&tab=buildLog&buildTypeId=Paddle_PrCi&logTab=tree&filter=all

[chengduoZH]

LGTM

[luotao1]

@kbinias