[non-BE][split-non-BE][allow-regression] Resolve "Probable porting bug in ivas_sba_dirac_stereo_compute_td_stefi_nrgs"

• Related issues: #2521
• Requested reviewers: @tritthart

Reason why this change is needed

• Various bugfixes around the calculation of
  • hStereoDft->hb_nrg_subr
  • hStereoDft->hb_nrg_fx[]
• For example:
  • Wrong boundaries in FOR loops
  • Imprecise calculations
  • Not taking q-values of hStereoDft->hb_nrg_fx[] at all
  • ...

Description of the change

• Fix issues mentioned above

Affected operating points

• Small differences in the BWE region only.

Closes #2521