[nnc] Move DispatchParallel to external_functions (#70221)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/70221
Test Plan: Imported from OSS
Reviewed By: ZolotukhinM
Differential Revision: D33249149
Pulled By: IvanKobzarev
fbshipit-source-id: fa6b2535dc09229d72b1c45eaa75434477cdff5e
