Fix A16W4 shuffle weight and scale for aiter/main

[Rohan138]

aiter/main: https://github.com/ROCm/aiter/blob/main/aiter/ops/shuffle.py
aiter/355_wip: https://github.com/ROCm/aiter/blob/355_wip/aiter/ops/shuffle.py

Fixes shuffle_mxfp4_scale vs shuffle_scale_a16w4 differences, but the expected src input tensor shapes for shuffle_weight_a16w4 (e, n, k) and shuffle_scale_a16w4 (e * n, k) are internally inconsistent in aiter/main (ROCm/aiter#1341). We should probably go fix this in aiter main.

Purpose

Test Plan

Test Result

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[Rohan138]

cc @dllehr-amd @coderfeli PTAL

[dllehr-amd]

LGTM! Lets get these changes merged!