Convert CONFIG_BOARD_LATE_INIT to Kconfig

This converts the following to Kconfig:
   CONFIG_BOARD_LATE_INIT

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/stm32f769-disco_defconfig b/configs/stm32f769-disco_defconfig
index 09fbcc9..0cda06e 100644
--- a/configs/stm32f769-disco_defconfig
+++ b/configs/stm32f769-disco_defconfig
@@ -12,6 +12,7 @@
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="console=ttyS0,115200 earlyprintk consoleblank=0 ignore_loglevel"
 # CONFIG_USE_BOOTCOMMAND is not set
+CONFIG_BOARD_LATE_INIT=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_BOARD_EARLY_INIT_F=y