This PR enables 4x4 tile size in MFMA based dot operations.
Supported tiled dot is (4x64) x (64x4) -> (4x4) in MFMA layout.
However, actual dot operation should have at least 64 output elements, this is a limitation of other layouts appearing during result processing (i.e. blocked layout can not handle tensors smaller than wavesize).
For example, following dots are supported: (4x64) x (64x16) -> (4x16), (16x64) x (64x4) -> (16x4) or (8x64) x (64x8) -> (8x8)
Following dots are not supporter: (4x128) x (128x4) -> (4x4), (4x64) x (64x8) -> (4x8)
This is a first version of dot using mfma 4x4 instructions, with redundancy and reductions.
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