wifi: ath9k: Make arrays prof_prio and channelmap static const

Don't populate the read-only arrays prof_prio and channelmap
on the stack but instead make them static const. Also makes the
object code a little smaller.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20221005155558.320556-1-colin.i.king@gmail.com