Add device tree source for the TP-Link Archer AX55 v1 [1]
which is a dual-band WiFi router based on the IPQ5018 SoC.

At the moment, only the UART, the GPIO LEDs and buttons
are usable, but it makes it possible to boot an initramfs
image on the device.

The device tree can be extended in the future, once support
for other periherals will be available for the platform.

1. https://www.tp-link.com/en/home-networking/wifi-router/archer-ax55/v1/Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Link: https://lore.kernel.org/r/20240326-archer-ax55-v1-v4-2-dc5b54a4bb00@gmail.comSigned-off-by: Bjorn Andersson <andersson@kernel.org>