[mamf-finder] add mxfp8 support

[stas00]

wip - seems to work - not sure if most optimal

./mamf-finder.py --m_range 0 20480 256 --n_range 0 20480 256 --k_range 0 20480 256 --output_file=$(date +"%Y-%m-%d-%H:%M:%S").txt --dtype float8_e8m0fnu