Enable threading for XNNPACK ops. (#34547)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34547
This enables threading by passing a threadpool to xnnpack ops.
Test Plan:
python test/test_xnnpack_integration.py
Imported from OSS
Differential Revision: D20370553
fbshipit-source-id: 4db08e73f8c69b9e722b0e11a00621c4e229a31a
