simplify conv dnnlowp ops by not allowing fp32 in/out (#15758)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15758
DNNLOWP Conv operators became very complex due to many options. This diff simplifies them by not allowing fp32 in/out. This is OK for Conv operators because Conv operators are usually used in deep networks where quantizing and dequantizing using separate operators is not much overhead.
Reviewed By: csummersea
Differential Revision: D13587341
fbshipit-source-id: e88c919dae79d1c5b7d787ea539edf5bcb064afc
