ath79: add factory.bin for ALLNET ALL-WAP02860AC

ath79: add factory.bin for ALLNET ALL-WAP02860AC

This device is a Senao-based product
using hardware and software from Senao
with the tar-gz platform for factory.bin
and checksum verification at boot time
using variables stored in uboot environment
and a 'failsafe' image when it fails.

Extremely similar hardware/software to Engenius EAP1200H
and other Engenius APs with qca955x

Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Signed-off-by: Michael Pratt <mcpratt@pm.me>
(cherry picked from commit 37ea5d9a658a15783b0ac68583db9e67a43e960d)