wvsplitk templatized and better tuned for MI300 (opendatahub-io#132)

* improvements to wvSpltK

* wvsplt gemm; better handle MI300 and large A[] sizes

* lint fix

* Adjustments to better handle small weights in TP8.

* early-out bug fix

* better wave load balancing in wvSplt

* add missing skip for wvsplt_big

* Bug fix for wvSplt_big in load balancing at M4, lint fix.