ARM: dts: stm32: add Hardware debug port (HDP) on stm32mp157c-dk2 board

ARM: dts: stm32: add Hardware debug port (HDP) on stm32mp157c-dk2 board

On the stm32mp157fc-dk2 board, we can observe the hdp GPOVAL function on
SoC pin E13 accessible on the pin 5 on the Arduino connector CN13.
Add the relevant configuration but keep it disabled as it's used for
debug only.

Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Link: https://lore.kernel.org/r/20250711-hdp-upstream-v7-8-faeecf7aaee1@foss.st.com
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>