Static memory of FastConv binaural handle

As reported in #123 (closed), the static memory of the FastConv binaural handle is unused for a big part:

ivas_binRenderer_c 166 m:sizeof( BINRENDERER_CONV_MODULE ) - 9% 1x157466 157466

hBinRenConvModule = (BINRENDERER_CONV_MODULE_HANDLE) count_malloc( sizeof( BINRENDERER_CONV_MODULE ) )

The goal is to allocate only memory which is really needed.