Fix various typos

Found via codespell v2.1.dev0
`codespell -q 3 -L ans,filp,fils,hsi`

Update nl80211.h

Update version.sh

Update sections.c

Update sdrctl.h

Update sdrctl.c

Update nl80211_testmode_def.h

Update cmd.c

adding license and copyright headers

the side channel (timestamp, frequency offset, CSI, equalizer) feature

update source coed of: 4 fpga queues and better driver/fpga flow control to avoid crash. improved slice cfg and printing

fix the tsf warning in sdr.c and sdrctl

Jetmir: add tsf set command to sdrctl

initial commit