boards: arm: disco_l475_iot1 board DTS of the dma-cell on quadspi
boards: arm: disco_l475_iot1 board DTS of the dma-cell on quadspi

The stm32l47r soc has a dma of type dma-v2, so the cells have
only 3 elements,. This adpat for the quadspi periph.

Signed-off-by: Francois Ramu <b83adc7f8a23ee911a37fcb61c4033581aae0b7a@st.com>

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