Convert CONFIG_BOARD_ECC_SUPPORT to Kconfig

This converts the following to Kconfig:
   CONFIG_BOARD_ECC_SUPPORT

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-mvebu/Kconfig b/arch/arm/mach-mvebu/Kconfig
index 7d487f2..e17a55a 100644
--- a/arch/arm/mach-mvebu/Kconfig
+++ b/arch/arm/mach-mvebu/Kconfig
@@ -152,6 +152,7 @@
 
 config TARGET_DB_MV784MP_GP
 	bool "Support db-mv784mp-gp"
+	select BOARD_ECC_SUPPORT
 	select MV78460
 
 config TARGET_DS414
@@ -160,6 +161,7 @@
 
 config TARGET_MAXBCM
 	bool "Support maxbcm"
+	select BOARD_ECC_SUPPORT
 	select MV78460
 
 config TARGET_THEADORABLE
@@ -226,6 +228,9 @@
 	  device will still hang - it doesn't make sense to reset the board
 	  in such a case.
 
+config BOARD_ECC_SUPPORT
+	bool
+
 config SYS_BOARD
 	default "clearfog" if TARGET_CLEARFOG
 	default "helios4" if TARGET_HELIOS4