wifi: ath9k: fix repeated to words in a comment

Delete the redundant word 'to'.

Signed-off-by: Jilin Yuan <yuanjilin@cdjrlc.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220915030559.42371-1-yuanjilin@cdjrlc.com