Convert CONFIG_SYS_LOAD_ADDR to Kconfig

Now that we have consistent usage, migrate this symbol to Kconfig.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Rick Chen <rick@andestech.com>
diff --git a/configs/M53017EVB_defconfig b/configs/M53017EVB_defconfig
index 809a497..297541e 100644
--- a/configs/M53017EVB_defconfig
+++ b/configs/M53017EVB_defconfig
@@ -4,6 +4,7 @@
 CONFIG_ENV_SECT_SIZE=0x8000
 CONFIG_DEFAULT_DEVICE_TREE="M53017EVB"
 CONFIG_TARGET_M53017EVB=y
+CONFIG_SYS_LOAD_ADDR=0x40010000
 CONFIG_BOOTDELAY=1
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="root=/dev/mtdblock3 rw rootfstype=jffs2"