ath11k: Fix spelling mistake "incompaitiblity" -> "incompatibility"

There is a spelling mistake in an ath11k_warn message. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211006083217.349596-1-colin.king@canonical.com