Support was added as variant of 7530 (DEVICE_ALT0_*) in:
cb6f4be1 "ipq40xx: add support for FRITZ!Box 7520"
u-boot has a distinct config for it [0], built it.
[0] https://github.com/chunkeey/FritzBox-4040-UBOOT/pull/6
Signed-off-by: Andre Heider <a.heider@gmail.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>