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/secomx6quq7_defconfig b/configs/secomx6quq7_defconfig
index 3e9e329..2866bb0 100644
--- a/configs/secomx6quq7_defconfig
+++ b/configs/secomx6quq7_defconfig
@@ -6,6 +6,7 @@
 CONFIG_SECOMX6_2GB=y
 CONFIG_SYS_EXTRA_OPTIONS="ENV_IS_IN_MMC"
 CONFIG_BOOTDELAY=3
+CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="SECO MX6Q uQ7 U-Boot > "
 CONFIG_CMD_BOOTZ=y