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/rcar3_ulcb_defconfig b/configs/rcar3_ulcb_defconfig
index 0d0dd36..58dcd81 100644
--- a/configs/rcar3_ulcb_defconfig
+++ b/configs/rcar3_ulcb_defconfig
@@ -10,6 +10,7 @@
 CONFIG_SPL_TEXT_BASE=0xe6338000
 CONFIG_RCAR_GEN3=y
 CONFIG_TARGET_ULCB=y
+CONFIG_SYS_LOAD_ADDR=0x58000000
 CONFIG_FIT=y
 CONFIG_SUPPORT_RAW_INITRD=y
 CONFIG_USE_BOOTARGS=y