Convert CONFIG_BOARD_EARLY_INIT_F to Kconfig

This converts the following to Kconfig:
   CONFIG_BOARD_EARLY_INIT_F

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/meesc_dataflash_defconfig b/configs/meesc_dataflash_defconfig
index 5c25eeb..e715491 100644
--- a/configs/meesc_dataflash_defconfig
+++ b/configs/meesc_dataflash_defconfig
@@ -5,6 +5,7 @@
 CONFIG_FIT=y
 CONFIG_SYS_EXTRA_OPTIONS="AT91SAM9263,SYS_USE_DATAFLASH"
 CONFIG_BOOTDELAY=3
+CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_HUSH_PARSER=y
 # CONFIG_CMD_BDI is not set
 CONFIG_CMD_BOOTZ=y