Convert CONFIG_BOARD_SIZE_LIMIT to Kconfig

This converts the following to Kconfig:
   CONFIG_BOARD_SIZE_LIMIT

To do this, introduce CONFIG_HAS_BOARD_SIZE_LIMIT.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/ea-lpc3250devkitv2_defconfig b/configs/ea-lpc3250devkitv2_defconfig
index 8d9a905..ba8c796 100644
--- a/configs/ea-lpc3250devkitv2_defconfig
+++ b/configs/ea-lpc3250devkitv2_defconfig
@@ -9,6 +9,8 @@
 CONFIG_TARGET_EA_LPC3250DEVKITV2=y
 CONFIG_DEFAULT_DEVICE_TREE="lpc3250-ea3250"
 CONFIG_DISTRO_DEFAULTS=y
+CONFIG_HAS_BOARD_SIZE_LIMIT=y
+CONFIG_BOARD_SIZE_LIMIT=1048575
 CONFIG_SYS_LOAD_ADDR=0x80100000
 # CONFIG_ARCH_FIXUP_FDT_MEMORY is not set
 # CONFIG_AUTOBOOT is not set