ath6kl: Remove WARN_ON msg in Suspend path

In the current code, WOW resume is executed first from RX path
and ar->state is moved to ATH6KL_STATE_ON. When platform calls
ath6kl_sdio_resume() in CFG resume context, that time ar->state
could have moved to ON state. Printing WARN_ON(1) is void in
this context. Hence removing this.

Once WOW resume is removed from RX path, This WARN_ON msg can be
reverted.

Signed-off-by: Raja Mani <rmani@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>