issue: 2479 "Harmonize tcx_ltp_pitch_search_*(), tcx_ltp_find_gain_*fx()"

• Related issues: #2479 (closed)
• Requested reviewers: @multrus

Reason why this change is needed

• Harmonize
  • tcx_ltp_pitch_search() and tcx_ltp_pitch_search_ivas_fx()
  • tcx_ltp_find_gain() and tcx_ltp_find_gain_ivas_fx()

Description of the change

• Harmonize
  • tcx_ltp_pitch_search() and tcx_ltp_pitch_search_ivas_fx()
  • tcx_ltp_find_gain() and tcx_ltp_find_gain_ivas_fx()

Affected operating points

• All operating points are BE

Closes #2479 (closed)