Encoder functions converted to fixed point

[x] Ported hq_generic_hf_encoding functions with minor modifications
[x] Extend lsf tools converted to fixed point
[x] FindChannelRatio and AdjustChannelRatios functions converted to fixed point
[x] Converted/updated few functions in ivas_stereo_td_analysis.c file
[x] Few functions in stereo_dft_enc path converted