Reduced storage needed for golay code.

I don't have access to the hardware needed to test this change, but I believe it
to be correct. I have a feeling this should also speed up the golay encoding by
reducing the memory bandwidth and storage needed by `golay_encode24` by
(about) half.

The high bite of the `golay_encode23` table was always the index/32 so
there’s no real need to store it.

The same should be doable with two tables for decode, one of uint16_t
and one of uint8_t to reduce size by a quarter. This might not be
beneficial though, since it’ll mean two memory accesses, and the encode
is helped by being able to do a shift of v, but no such (easily
calculable) result exists in the decode values.

Currently doesn’t compile (I assume ECC was removed because it was using
too much space in RAM once other features were added), but hopefully
it’s a useful improvement saving some room for other data for those who are
using ECC.