wifi: ath11k: Enable threaded NAPI

Enable threaded NAPI on all ath11k targets. Unlike traditional
NAPI poll which runs in softirq context and on the core which
scheduled the NAPI, threaded NAPI makes use of kernel threads
which are under direct control of the scheduler and helps in
balancing the NAPI processing load across multiple CPUs thereby
improving throughput.

In the case of WCN6750, enabling threaded NAPI has improved
160 MHz RX throughput by nearly 400 Mbps. Similar gains can
be expected on other ath11k devices as well.

Tested-on: WCN6750 hw1.0 AHB WLAN.MSL.1.0.1-00887-QCAMSLSWPLZ-1

Signed-off-by: Manikanta Pubbisetty <quic_mpubbise@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220905071805.31625-2-quic_mpubbise@quicinc.com