[non-BE][split-non-be] Resolve "Level drop in ISMx formats at higher bitrates"

• Related issues: #1028 (closed)
• Requested reviewers: @fotopoulou

Reason why this change is needed

Solve the 1dB level drop observed with the TCX core at higher bitrates.

Description of the change

Harmonize the logix setting the LP weighting factor st->gamma between the TCX encoder and the TCX decoder.

Affected operating points

This is a non-BE fix affecting all operating points and quality should be carefully reviewed.