[QNN EP] Add Static bias encoding support for Conv op (#26710)
- Fix QNN-EP to support static bias tensors with mismatched quantization
encodings
- Add requantization logic to ensure bias_scale = weights_scale x
activation_scale
### Description
The QNN-EP currently lacks support for static bias tensors with
quantization encodings that don't match the expected mathematical
relationship bias_scale = weights_scale × activation_scale.
### Motivation and Context
This leads to HTP backend disregard the encodings of the bias tensor and
recompute its own causing accuracy drops
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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: qti-ashwshan <ashwshan@qti.qualcomm.com>