Update nGraph to version 0.26 (#1965)
* Adjust ngraph cmake files to onnx 1.5.0
* Enable LSTM reverse direction mode in nGraph EP
* Enable full support for the Split op in nGraph EP
* Revert "Disable the unsigned input Shrink op tests for nGraph until the next update"
This reverts commit 257b42a55bdd98f804d4846868542b8e3aeb4b4e.
* Enable Gather and remove unused subgraph attribute
* Remove the unused param from AppendClusterToSubGraph
* Fix for the incorrect onnx opset version
* Use the r0.26 release branch before the tag is created
* Enable the quantizelinear and dequantizelinear for NGEP
* Use the v0.26.0-rc.2 tag in ngraph.cmake
* Add skip for modes others than default in Pad operator
* Reenable negative axis tests for ngraph
* Use temporary ngraph version
* Use branch name instead of SHA for temporary ngraph branch
* Use ngraph v0.26.0-rc.4
* Remove patch for missing symbol in MKLDNN
* Use MKLDNN 1.0 in ngraph
* Exclude the Pad op for opsets greater than 10
* Disable quantizelinear and dequantizelinear tests for ONNX 1.5.0
* Fix the onnx-headers related compilation errors
* ONNX libs linking fix
* Use a tag for ngraph and support more Pad modes
* Use the v0.26.0 release tag for nGraph
* Update ngraph to RC8 - bigobj flag for Windows builds
* Fix the MKLDNN constexpr error on Windows
