ath10k: migrate to mac80211 txq scheduling

ath10k maintains common txqs list for all stations. This txq
management can be removed by migrating to mac80211 txq APIs
and let mac80211 handle txqs reordering based on reported airtime.
By doing this, txq fairness maintained in ath10k i.e processing
N frames per txq is removed. By adapting to mac80211 APIs,
ath10k will support mac80211 based airtime fairness algorithm.

Tested on QCA4019 with firmware version 10.4-3.2.1.1-00015
Tested on QCA9984 with firmware version 10.4-3.9.0.1-00005

Tested-by: Venkateswara Naralasetty <vnaralas@codeaurora.org>
Co-developed-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>