boards: st: stm32h7s78_dk: add support for touch input

Add support for the touch input controller on the STM32H7S78-DK:
- Enable I2C1 on the board
- Add device tree node for the touch controller in the display panel

Signed-off-by: Titouan Christophe <titouan.christophe@mind.be>
3 files changed