bx50v3: Enable CONFIG_OF_LIBFDT in defconfig

As of commit 69e173eb57d1f4848f070c83456096ba5d2ba1b4, CONFIG_OF_LIBFDT
needs to be selected in defconfig instead of board specific header file.
Hence enable CONFIG_OF_LIBFDT in defconfig.

Signed-off-by: Akshay Bhat <akshay.bhat@timesys.com>

configs/ge_b450v3_defconfig

@@ -6,3 +6,4 @@ CONFIG_TARGET_GE_B450V3=y
 CONFIG_CMD_GPIO=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_STMICRO=y
+CONFIG_OF_LIBFDT=y

configs/ge_b650v3_defconfig

@@ -6,3 +6,4 @@ CONFIG_TARGET_GE_B650V3=y
 CONFIG_CMD_GPIO=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_STMICRO=y
+CONFIG_OF_LIBFDT=y

configs/ge_b850v3_defconfig

@@ -6,3 +6,4 @@ CONFIG_TARGET_GE_B850V3=y
 CONFIG_CMD_GPIO=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_STMICRO=y
+CONFIG_OF_LIBFDT=y

include/configs/ge_bx50v3.h

@@ -302,8 +302,6 @@
 #define CONFIG_ENV_SPI_MODE		CONFIG_SF_DEFAULT_MODE
 #define CONFIG_ENV_SPI_MAX_HZ		CONFIG_SF_DEFAULT_SPEED
 
-#define CONFIG_OF_LIBFDT
-
 #ifndef CONFIG_SYS_DCACHE_OFF
 #define CONFIG_CMD_CACHE
 #endif