cleanup in pitch_ol

• Related issues: #2403 (closed)
• Requested reviewers: @vaclav

Reason why this change is needed

• IVAS pitch ol is using 64 bits for correlation computation, but the processing to select the final pitch is the same between IVAS and EVS, saving around 300 Lns

Description of the change

• Creation of a static function that includes the common code of the both IVAS and EVS pitch open loop processing.

Affected operating points

• Everything should be BE

  close #2403 (closed)