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/P1020UTM-PC_SDCARD_defconfig b/configs/P1020UTM-PC_SDCARD_defconfig
index c03c7c5..c609e6f 100644
--- a/configs/P1020UTM-PC_SDCARD_defconfig
+++ b/configs/P1020UTM-PC_SDCARD_defconfig
@@ -13,6 +13,7 @@
 CONFIG_OF_STDOUT_VIA_ALIAS=y
 CONFIG_SYS_EXTRA_OPTIONS="SDCARD"
 CONFIG_BOOTDELAY=10
+CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_SPL=y
 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT=y
 CONFIG_HUSH_PARSER=y