Kconfig: Migrate BOARD_LATE_INIT to a select

This option should not really be user selectable.  Note that on PowerPC
we currently only need BOARD_LATE_INIT when CHAIN_OF_TRUST is enabled so be
conditional on that.

Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> (for UniPhier)
diff --git a/common/Kconfig b/common/Kconfig
index bb47ee4..f045a16 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -374,7 +374,7 @@
 	  next reset.
 
 config BOARD_LATE_INIT
-	bool "Enable Board late init code"
+	bool
 	help
 	  Sometimes board require some initialization code that might
 	  require once the actual init done, example saving board specific env,