Quantized LSTM/GRU: Remove legacy API support (#72522)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/72522
Ref #72263 for cpp_custom_type_hack removal
These overloads were deprecated in #35787 which was in the PyTorch 1.6
release, so the BC period is well expired.
cc jamesr66a
Test Plan: Imported from OSS
Reviewed By: bdhirsh
Differential Revision: D34111271
Pulled By: albanD
fbshipit-source-id: 0078564188133625ca67137975fd5dd2fa2b4827
(cherry picked from commit 4f9c5a3ed7cd072dc973f3f995f1a8c6cf06b451)