This is a USRobotics NAS/Firewall/router that has been supported
by OpenWrt in the past. It had dedicated users so let's get it
properly supported.
Some debugging and fixing was provided by Howard Harte.
Link: https://lore.kernel.org/r/20231007-ixp4xx-usr8200-v1-1-aded3d6ff6f1@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>