mac80211: ath: improve ath10k "failed to flush transmit queue" errors

mac80211: ath: improve ath10k "failed to flush transmit queue" errors

Currently, in busy environments, ath10k logs "failed to flush transmit
queue" errors and have a spiking CPU usage, making the wireless barely
usable.
With this patch, taken from https://patchwork.kernel.org/project/linux-wireless/patch/20250806070005.1429-1-hujy652@gmail.com/
this does not occur in normal operation and the wifi is much more stable

Supersedes #19427
Ref: https://github.com/openwrt/openwrt/issues/15929#issuecomment-2227391307
Ref: https://github.com/openwrt/openwrt/issues/14965

Signed-off-by: Florian Maurer <f.maurer@outlook.de>
Link: https://github.com/openwrt/openwrt/pull/19529
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>