mac80211: add ath11k PCI support

mac80211: add ath11k PCI support

ath11k is the upstream driver for Qualcomm 802.11ax radios, both for the
internal AHB and PCI based cards.
This commit does however only provide PCI support while AHB will follow
but its SoC specific so it will require an OpenWrt target first.

It differs a bit from ath10k as it requires stuff like QRTR, MHI and QMI
helpers.

PCI variant requires qrtr-mhi and mhi-bus which backports do provide,
however we are dropping those in a patch as they will conflict with
support for the AHB variant as that one requires qrtr-smd which in turn
requires RPMSG and GLINK and its not feasable to provide those in
backports as they are really SoC specific.

QRTR and MHI in kernel 5.10 are not usable and backporting the changes
is not easy as they have changed drastically from 5.10 to 5.15 ath11k will
only be available on targets that use kernel 5.15.

Signed-off-by: Robert Marko <robimarko@gmail.com>