stm32f7: enable board info read from device tree

Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
cc: Christophe KERELLO <christophe.kerello@st.com>

include/configs/stm32f746-disco.h

@@ -72,4 +72,5 @@
 #define CONFIG_CMD_MEM
 #define CONFIG_CMD_CACHE
 #define CONFIG_BOARD_LATE_INIT
+#define CONFIG_DISPLAY_BOARDINFO
 #endif /* __CONFIG_H */