Complexity reduction of formulate2x2MixingMatrix()

formulate2x2MixingMatrix() can be simplified if there are no cross-terms (CinRe, CinIm == 0), which is every second call the case. Also the basop/float ratio of > 2 can be brought down if after the energy normalization to 1.0 only native BASOPS are used in the calculation instead of using a mantissa/exponent format which requires scaling operations and the usage of the BASOP_Util_Add_Mant32Exp() function

• Decoder (float):2164c51655b6cd58252eebe4de0d4dacfa89f506

ivas_dirac_dec_binaural_determine_processing_matrices[WMC_AUTO]     4.00    2.688   2.688   2.688   22.154  22.821  22.783

• Decoder (BASOP): e18c9336

ivas_dirac_dec_binaural_determine_processing_matrices_fx[WMC_AUTO]     4.00    3.347   3.377   3.363   39.262  49.088  48.784