Update NNPACK (#49749)
Summary:
This update enables NNPACK cross compilation on MacOS
Pull Request resolved: https://github.com/pytorch/pytorch/pull/49749
Reviewed By: janeyx99
Differential Revision: D25683056
Pulled By: malfet
fbshipit-source-id: c7a6b7f49d61a9a0697d67f6319f06bd252b66a5
