[quant][fx][fix] Fused modules with object_type in qconfig (#60779)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60779
When we do fusion, we replace certain modules (such as Linear + ReLU) with fused versions (such as LinearReLU) by calling `_fuse_fx` in prepare_fx. However when we try to look up using the fused module type in qconfig_dict, we cannot find a match anymore since the qconfig dict contains the original module types. An example is here [N882873](https://fburl.com/anp/azenjx3v).
So we will now update the qconfig_dict to include the fused modules mapping to the qconfigs used for the modules that make up the fused modules. If the modules are not mapped to the same qconfig, then we will raise an error.
Test Plan:
`python test/test_quantization.py TestFuseFx.test_qconfig_fused_module`
Imported from OSS
Reviewed By: supriyar
Differential Revision: D29406941
fbshipit-source-id: 74b5db89f4998aeb02b2bf7c37bf97326580c654
