[Quant] Add quantized input tensor data type checks (#71218)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71218
This asserts quint8 support, and fails with a helpful error message when attempted to use with a different qdtype
Test Plan: buck test caffe2/test:quantization
Reviewed By: kimishpatel
Differential Revision: D33455785
fbshipit-source-id: 6ec728f59bb707c2d941b50e6375a698c66284c0
