stm32f746: to switch on user LED1 & read user button

All discovery boards have one user button & one user LED. Here we are
just reading the button status & switching ON the user LED.

Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
cc: Christophe KERELLO <christophe.kerello@st.com>
diff --git a/include/configs/stm32f746-disco.h b/include/configs/stm32f746-disco.h
index e917ba9..48ac441 100644
--- a/include/configs/stm32f746-disco.h
+++ b/include/configs/stm32f746-disco.h
@@ -75,4 +75,5 @@
 
 #define CONFIG_CMD_MEM
 #define CONFIG_CMD_CACHE
+#define CONFIG_BOARD_LATE_INIT
 #endif /* __CONFIG_H */