Convert CONFIG_SPL_BOARD_INIT to Kconfig

This converts the following to Kconfig:
   CONFIG_SPL_BOARD_INIT

Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>
[trini: Update the Kconfig logic]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/m53evk_defconfig b/configs/m53evk_defconfig
index b0379b8..a7bf297 100644
--- a/configs/m53evk_defconfig
+++ b/configs/m53evk_defconfig
@@ -15,6 +15,7 @@
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_VERSION_VARIABLE=y
 CONFIG_SPL=y
+CONFIG_SPL_BOARD_INIT=y
 CONFIG_HUSH_PARSER=y
 # CONFIG_CMD_IMLS is not set
 CONFIG_CMD_ASKENV=y