ARM: dts: stm32: Enable thermal sensor support on STM32MP157c-ed1

Enable STM32 Digital Thermal Sensor (dts) driver for STM32MP157c-ed1 board.

Signed-off-by: David Hernandez Sanchez <david.hernandezsanchez@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>