[pytorch] Move TensorIteratorConfig method implementation to cpp file (#43554)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/43554
Move function implementations in the TensorIteratorConfig Class from TensorIterator.h to TensorIterator.cpp to avoid this issue: https://github.com/pytorch/pytorch/issues/43300
Reviewed By: malfet
Differential Revision: D23319007
fbshipit-source-id: 6cc3474994ea3094a294f795ac6998c572d6fb9b
