Revert "mac80211 adjust QCA9561 PA bias"

Revert "mac80211 adjust QCA9561 PA bias"

This reverts commit f9ff282d17ec652d63fa2404e47bb0e15ed95b69 as during
upstream patch review process nbd pointed out, that this patch needs
more work:

 "The patch looks wrong to me. I'm pretty sure that AR_CH0_TOP2 is the
  correct register, the definition has an explicit check for 9561 as well.
  I believe this patch works by accident because it avoids writing a wrong
  value to that register."

1. https://lore.kernel.org/all/91c58969-c60e-2f41-00ac-737786d435ae@nbd.name

Signed-off-by: Petr Štetiar <ynezz@true.cz>