ath6kl: Isolate host sleep mode config part from ath6kl_wow_suspend

The piece of code used in ath6kk_wow_suspend function
to configure the host sleep mode is needed in deep sleep
case also.

Moving that portion to a separate function called
ath6kl_update_host_mode() would be helpful to avoid
the duplication of the same code in deep sleep path.

There is no functional change.

kvalo: move inline functions to cfg80211.c and fix a long line

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