Just when resume from WoW, the write to select_window doesn't take
effect immediately, so read the register again to ensure the write
operation is finished.

Another change is to reset select_window to ZERO because this
register isn't restored after WoW, so the content of this register
becomes ZERO too.

Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1
Signed-off-by: NCarl Huang <cjhuang@codeaurora.org>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1607708150-21066-4-git-send-email-kvalo@codeaurora.org