Add support for the lxa-tac generation 3 board based on the STM32MP153c. Signed-off-by: Leonard Göhrs <l.goehrs@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>