boards: stm32f769i_disco: Add SDMMC Support
boards: stm32f769i_disco: Add SDMMC Support

Add board specific configuration for  SDMMC support

Signed-off-by: Mohamed ElShahawi <70fedd2386caf7413994d68d6567349c29d099d2@hotmail.com>

galak/zephyr,Vudentz/zephyr,Vudentz/zephyr,finikorg/zephyr,Vudentz/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,galak/zephyr,galak/zephyr,Vudentz/zephyr,nashif/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,Vudentz/zephyr,Vudentz/zephyr,nashif/zephyr,finikorg/zephyr