Resolve "Harmonize enc_prm_fx()"

• Related issues: #2606 (closed)
• Requested reviewers: @fotopoulou

Reason why this change is needed

• Bring enc_prm_fx() inline with float

Description of the change

• Bring enc_prm_fx() inline with float

Affected operating points

• Affects only EVS. BE Change.

Closes #2606 (closed)