ath10k: workaround qca6174 sta powersave issue

qca6184 WLAN.RM.2.0-00073 has a bug in sta
powersave state machine and requires peer param to
be poked to enable the powersave.

Calling this unconditionally should be safe for
other chips/firmwares.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>