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/trats_defconfig b/configs/trats_defconfig
index 5709c4f..a04e242 100644
--- a/configs/trats_defconfig
+++ b/configs/trats_defconfig
@@ -8,6 +8,7 @@
 CONFIG_ENV_OFFSET=0x7000
 CONFIG_DEFAULT_DEVICE_TREE="exynos4210-trats"
 CONFIG_DISTRO_DEFAULTS=y
+CONFIG_SYS_LOAD_ADDR=0x44800000
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_USE_BOOTARGS=y