wil6210: interrupt: Demote comment header which is clearly not kernel-doc

Fixes the following W=1 kernel build warning(s):

 drivers/net/wireless/ath/wil6210/interrupt.c:652: warning: Function parameter or member 'irq' not described in 'wil6210_thread_irq'
 drivers/net/wireless/ath/wil6210/interrupt.c:652: warning: Function parameter or member 'cookie' not described in 'wil6210_thread_irq'

Cc: Maya Erez <merez@codeaurora.org>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-wireless@vger.kernel.org
Cc: wil6210@qti.qualcomm.com
Cc: netdev@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200827073338.GS3248864@dell