arm_cmplx_mag_q15 reworked to be more accurate but less efficient.
New function arm_cmplx_mag_fast_q15 introduced to retain previous
(less accurate) but faster behavior.
Improvement to Python wrapper to support the new functions.
MFCC F32 implementation
MFCC F32 tests
MFCC F32 in Python wrapper
Python wrapper structure updated to support submodule like
cmsisdsp.mfcc and cmsisdsp.fixedpoint
PythonWrapper tests updated to use the new fixedpoint
cmsisdsp.mfcc is used to generate the mel filter, dct and window coefficients.
Christophe Favergeon