ath6kl: Optimize target power in deep sleep suspend

Adding below steps helps to get good power numbers
in deep sleep suspend path,

    * Disable WOW mode.
    * Flush data packets and wait for all control packets.
      to be cleared in TX path before deep sleep suspend.
    * Set host sleep mode to SLEEP.

Below steps are added to perform the recovery action
while the system resume from deep sleep,

     * Set host sleep mode to AWAKE.
     * Reset scan parameters to default value.

In addition, Debug prints are added to track deep sleep
suspend/resume state.

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