Fixed point related updates to decoder_tcx_invQ func calls.

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

MLD:
Original: 8 cases > 5
8.622747 9.196089 12.937471 22.589209 37.374386 37.677368 38.38456 39.393681

+10dB: 17 cases > 5
5.665263 5.665263 6.416382 7.0239 10.756404 10.756404 14.899035 16.599049 16.975687 23.380634 23.678699 27.051519 50.451431 50.466957 51.933289 51.966801 52.359127

-10dB: 7 cases > 5
8.664676 15.849977 25.000893 25.884504 26.076967 26.733379 27.37816

MLD deviation issue to be debugged.