board: stm32f429-discovery: switch to DM STM32 sdram driver

Use available DM stm32_sdram.c driver instead of board
SDRAM initialization.
For that, enable OF_CONTROL, OF_EMBED and STM32_SDRAM flags.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
3 files changed