dt-bindings: arm: stm32: add compatible strings for Linux Automation GmbH LXA FairyTux 2

dt-bindings: arm: stm32: add compatible strings for Linux Automation GmbH LXA FairyTux 2

The Linux Automation GmbH FairyTux2 is a small Linux device based on
an Octavo Systems OSD32MP153c SiP, that occupies just two slots on a
DIN rail.

Add compatible for the generation 1 and 2 based on the STM32MP153c.

Signed-off-by: Leonard Göhrs <l.goehrs@pengutronix.de>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>