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/fo300_defconfig b/configs/fo300_defconfig
index dd2f965..280ea8c 100644
--- a/configs/fo300_defconfig
+++ b/configs/fo300_defconfig
@@ -9,6 +9,7 @@
 CONFIG_SILENT_CONSOLE=y
 # CONFIG_CONSOLE_MUX is not set
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
+CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_ASKENV=y
 CONFIG_LOOPW=y