Remove `_bfp` from functions that aren't BFP specific

[oscarbailey-xmos]

There are several functions e.g. dsp_bfp_clz_uint8 that only take a single argument. The _bfp label in a function name should only be used for functions that are BFP specific and can't be used for non-bfp data.
This would simplify other function names too: _vect could be removed from all _bfp functions since _bfp implies _vect