ath10k: set SM power save disabled to default value

Use SMPS disabled as default because FW does not indicate
any support of SMPS.

This change will help STAs out that don’t support SMPS from
sticking on 1SS, since they don’t have method to change it
back to multiple chains.

This change also should not affect power consumption of STAs
supporting SMPS, because they are capable to switch the mode
to dynamic or static either at the end of frame sequence or
by using SMPS action frame.

Signed-off-by: Peter Oh <poh@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>