Rename NMD::extract_ft_20_19_18_17_16(uint64 instruction) to
NMD::extract_ft_25_24_23_22_21(uint64 instruction).

Reviewed-by: Aleksandar Rikalo <arikalo@wavecomp.com>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>