migrate export_caffe2_op_to_c10.h macros to the new dispatcher registration API (#48097)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/48097
Test Plan: Imported from OSS
Reviewed By: ezyang
Differential Revision: D25056091
Pulled By: bdhirsh
fbshipit-source-id: 0f647ab9bc5e5aee497dac058df492f6e742cfe9
