Add BF16 dtype mapping for python EVT

[gau-nernst]

Fixes #1824

I was thinking of adding a test case for this, but currently the dtype is hard-coded to FP16

cutlass/test/python/cutlass/evt/utils/evt_testbed.py

Line 206 in 44dae8b

self.element = cutlass.DataType.f16

Would take some refactoring to test multiple dtypes at the same time. Lmk if you want to add any tests, or don't add anything is fine.

@jackkosaian

[jackkosaian]

Thanks! No worries about adding tests. I'll run this through internally and get back about the ability to merge.