Review code in stereo_dft_enc_compute_itd()

Bug description

One of the loops in stereo_dft_enc_compute_itd() has different boundaries in BASOP compared to float:

Float:

for ( i = 1; i < NFFT / 2; i++ )
{
    /* Low pass filter cross L/R power spectrum */
    hStereoDft->xspec_smooth[2 * i] = ( 1.f - cng_xcorr_filt ) * hStereoDft->xspec_smooth[2 * i] + cng_xcorr_filt * xcorr[2 * i];
    hStereoDft->xspec_smooth[2 * i + 1] = ( 1.f - cng_xcorr_filt ) * hStereoDft->xspec_smooth[2 * i + 1] + cng_xcorr_filt * xcorr[2 * i + 1];

    /* Low pass filter L/R power spectrum */
    /* Calculate coherence as cross spectral density divided by L*R power spectrum */
    hStereoDft->Spd_L_smooth[i] = ( 1.f - cng_xcorr_filt ) * hStereoDft->Spd_L_smooth[i] + cng_xcorr_filt * Spd_L[i];
    hStereoDft->Spd_R_smooth[i] = ( 1.f - cng_xcorr_filt ) * hStereoDft->Spd_R_smooth[i] + cng_xcorr_filt * Spd_R[i];
}

BASOP:

FOR( i = 1; i < NFFT / 4; i++ )
{
    /* Low pass filter cross L/R power spectrum */
    // hStereoDft->xspec_smooth[2 * i] = ( 1.f - cng_xcorr_filt ) * hStereoDft->xspec_smooth[2 * i] + cng_xcorr_filt * xcorr[2 * i];
    hStereoDft->xspec_smooth_fx[2 * i] = BASOP_Util_Add_Mant32Exp( Mpy_32_32( L_sub( MAX_32, cng_xcorr_filt ), hStereoDft->xspec_smooth_fx[2 * i] ), hStereoDft->xspec_smooth_fx_e[2 * i], Mpy_32_32( cng_xcorr_filt, xcorr[2 * i] ), xcorr_e[2 * i], &hStereoDft->xspec_smooth_fx_e[2 * i] );
    move32();
    // hStereoDft->xspec_smooth[2 * i + 1] = ( 1.f - cng_xcorr_filt ) * hStereoDft->xspec_smooth[2 * i + 1] + cng_xcorr_filt * xcorr[2 * i + 1];
    hStereoDft->xspec_smooth_fx[2 * i + 1] = BASOP_Util_Add_Mant32Exp( Mpy_32_32( L_sub( MAX_32, cng_xcorr_filt ), hStereoDft->xspec_smooth_fx[2 * i + 1] ), hStereoDft->xspec_smooth_fx_e[2 * i + 1], Mpy_32_32( cng_xcorr_filt, xcorr[2 * i + 1] ), xcorr_e[2 * i + 1], &hStereoDft->xspec_smooth_fx_e[2 * i + 1] );
    move32();

    /* Low pass filter L/R power spectrum */
    /* Calculate coherence as cross spectral density divided by L*R power spectrum */
    // hStereoDft->Spd_L_smooth[i] = ( 1.f - cng_xcorr_filt ) * hStereoDft->Spd_L_smooth[i] + cng_xcorr_filt * Spd_L[i];
    hStereoDft->Spd_L_smooth_fx[i] = BASOP_Util_Add_Mant32Exp( Mpy_32_32( L_sub( MAX_32, cng_xcorr_filt ), hStereoDft->Spd_L_smooth_fx[i] ), Spd_L_smooth_fx_tmp_e[i], Mpy_32_32( cng_xcorr_filt, Spd_L[i] ), Spd_L_e[i], &Spd_L_smooth_fx_tmp_e[i] );
    move32();
    hStereoDft->Spd_R_smooth_fx[i] = BASOP_Util_Add_Mant32Exp( Mpy_32_32( L_sub( MAX_32, cng_xcorr_filt ), hStereoDft->Spd_R_smooth_fx[i] ), Spd_R_smooth_fx_tmp_e[i], Mpy_32_32( cng_xcorr_filt, Spd_R[i] ), Spd_R_e[i], &Spd_R_smooth_fx_tmp_e[i] );
     move32();
}