Allow parsing of E4M3FN models using scales manipulation

[umangyadav]

If the E4M3FN model is quantized using QDQ pairs then, it can be converted into E4M3FNUZ types by multiplying scales with some constants.

This would allow using E4M3FN models inside MIGraphX.

[fxmarty]

@umangyadav I am curious whether there is a conversion E4M3FN + scale <-> E4M3FNUZ + scale implemented anywhere?

[umangyadav]

@fxmarty We don't have that logic implemented in MIGraphX yet. I have an issue open that describes the logic https://github.com/ROCm/AMDMIGraphX/issues/2717 It's pretty simple to convert, but haven't had chance to work on it.