Mx fp6 flatmm (#3601)

* add fp6 data-type and support sync/async dwordx3 load/store

* clang-format

* pre-commit

* 1st commit

* default mnk pass ut

* fix a distrubution

* fix

* fix bdram distr

* update

* pass ut

* improve perf

* update

* clean code

* resolve copilot comment

* reslove comment

* clang-format

---------

Co-authored-by: ZheWang <zhewan@amd.com>