ivas_omasa_com functions converted to fixed point.

[x] Below functions present in ivas_omasa_com file are converted to fixed point.
ivas_omasa_ism_mode_select
ivas_set_omasa_TC
ivas_interformat_brate
ivas_combined_format_brate_sanity
bits_index_ism_ratio
calculate_nbits_meta
ivas_get_stereo_panning_gains - does not get hit by any test stream,test is done through unit testing.

Pytests: 573 failed, 381 skipped and 1 passed for original inputs, +10dB scaled and -10dB scaled inputs.

MLD: Original: 4 cases > 5 8.623086 9.196089 12.944769 22.460232

+10dB: 16 cases > 5 5.35562 5.52244 5.663041 5.663041 6.294713 6.992652 9.476715 10.755767 10.755767 14.898742 16.605692 16.975687 23.383167 24.858898 27.042179 51.74955

-10dB: 3 cases > 5 8.66535 15.850086 24.996883

MLD deviation issue to be debugged.