Many integrated QCA9984 WiFis in various IPQ806x platform routers
from various vendors (Netgear R7800, ZyXEL NBG6817, TP-LINK C2600,
etc.) have either blank, bogus or non-unique MAC-addresses in
their calibration data.

As a result, OpenWrt utilizes a discouraged binary calibration data
patching method that allows to modify the device's MAC-addresses right
at the source. This is because the ath10k' firmware extracts the MAC
address from the supplied radio/calibration data and issues a response
to the ath10k linux driver. Which was designed to take the main MAC in
ath10k_wmi_event_ready().

Part of the "setting an alternate MAC" issue was already tackled by a
patch from Brian Norris:
commit 9d580466
("ath10k: retrieve MAC address from system firmware if provided")
by allowing the option to specify an alternate MAC-address with the
established device_get_mac_address() function which extracts the right
address from DeviceTree/fwnode mac-address or local-mac-address
properties and saves it for later.

However, Ben Greear noted that the Qualcomm's ath10k firmware is liable
to not properly calculate its rx-bssid mask in this case. This can cause
issues in the popluar "multiple AP with a single ath10k instance"
configurations.

To improve MAC address handling, Felix Fietkau suggested to call
pdev_set_base_macaddr_cmdid before bringing up the first vif and
use the first vif MAC address there. Which is in ath10k_core_start().

This patch implement Felix Fietkau's request to
"call pdev_set_base_macaddr_cmdid before bringing up the first vif".
The pdev_set_base_macaddr_cmdid is already declared for all devices
and version. The driver just needed the support code for this
function.

Tested on:
QCA9880/CUS223, firmwares: 10.2.4.13-2, 10.2.4.70.44, 10.2.4-1.0-00041
QCA9887/MR33 firmware:10.2.4-1.0-00033
QCA4019/RT-AC58U firmware: 10.4-3.4-00104, 10.4-3.5.3-00057
QCA9984/R7800 firmware: Candela Technologies (CT) Firmware

BugLink: https://lists.openwrt.org/pipermail/openwrt-devel/2018-November/014595.html
Fixes: 9d580466 ("ath10k: retrieve MAC address from system firmware if provided")
Cc: Brian Norris <briannorris@chromium.org>
Cc: Ben Greear <greearb@candelatech.com>
Cc: Felix Fietkau <nbd@nbd.name>
Cc: Mathias Kresin <dev@kresin.me>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Tested-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>