ipq-wifi: fix upstream board-2.bin ZTE M289F snafu

ipq-wifi: fix upstream board-2.bin ZTE M289F snafu

The upstream board-2.bin file in the linux-firmware.git
repository for the QCA4019 contains a packed board-2.bin
for this device for both 2.4G and 5G wifis. This isn't
something that the ath10k driver supports.

Until this feature either gets implemented - which is
very unlikely -, or the upstream boardfile is mended
(both, the original submitter and ath10k-firmware
custodian have been notified). OpenWrt will go back
and use its own bespoke boardfile. This unfortunately
means that 2.4G and on some revisions the 5G WiFi is
not available in the initramfs image for this device.

Fixes: #12886
Reported-by: Christian Heuff <christian@heuff.at>
Debugged-by: Georgios Kourachanis <geo.kourachanis@gmail.com>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>