arm64: dts: st: enable display support on stm32mp257f-ev1 board

arm64: dts: st: enable display support on stm32mp257f-ev1 board

Enable the following IPs on stm32mp257f-ev1 in order to get display:
   * LTDC
   * LVDS
   * WSVGA LVDS panel (1024x600)
   * Panel LVDS backlight as GPIO backlight
   * ILI2511 i2c touchscreen

Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
Acked-by: Yannick Fertre <yannick.fertre@foss.st.com>
Link: https://lore.kernel.org/r/20250822-drm-misc-next-v5-13-9c825e28f733@foss.st.com
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>