[CK Tile][MFMA/WMMA unification] Add support for packed datatypes (tiny types) (#6088)
## Motivation
This MR makes all the changes required for the unified architecture to
be able to deal with packed datatypes i.e. int4, fp4, fp6, and bf6. The
crux is that layout parameters should be interpreted as describing the
pure mathematical matrix fragments, while the ext_vectors and tile
distribution encodings describe everything in terms of packed datatype
units. This matches how packed types are dealt with in ck_tile and
should play nicely with the load and store tile ops once we integrate
the unified framework into CK tile.
The bf6 datatype was added to CK tile in the form of pk_bf6x16_t and
pk_bf6x32_t, which did not exist before.
The ext_vector implementations of pk_fp6x16_t and pk_bf6x16_t (vec size
1 and 2) were extended to make the subscripting operator work as
expected.
The layout test was adapted to be compatible with all packed datatypes,
and all new intrinsics were added to the test.
This MR adds ALL intrinsics across ALL architectures which use packed
datatypes, as well as ALL scale intrinsics:
mfma_scale_f32_16x16x128_f8f6f4 gfx950 (F8xF8, BF8xBF8, F4xF4, F6xF6,
BF6xBF6)
mfma_scale_f32_32x32x64_f8f6f4 gfx950 (F8xF8, BF8xBF8, F4xF4, F6xF6,
BF6xBF6)
wmma_i32_16x16x16_iu4_w32
wmma_i32_16x16x16_iu4_w32_gfx12
wmma_i32_16x16x32_iu4_w32_gfx12
## Testing
All intrinsics were tested on all architectures.
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