QCA6390 power saving issue

[Mark Herbert]

I remember there was a bug preventing CPU entering to deep powersaving 
states so only PC3 was reached.

The but itself is fixed - but I have just noticed a small remaining 
issue. When I start my PC and there is no WIFI that I can connect so 
ath11  is enabled but not connected to any network - it   prevents 
entering into deep PC states again. When I connect to the WiFi network - 
deep PC states become reachable again. And when I disconnect after first 
connection  and keep my ath11k disconnected (exactly same situation as 
immediately after boot)- there is no issue.

So seems that this powersaving feature is not activated on boot but only 
activates when the card connects to access point.  I am not good enough 
in driver development and design a fix myself. So just writing here