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/uniphier_ld4_sld8_defconfig b/configs/uniphier_ld4_sld8_defconfig
index 5a2b414..7f17f79 100644
--- a/configs/uniphier_ld4_sld8_defconfig
+++ b/configs/uniphier_ld4_sld8_defconfig
@@ -10,6 +10,7 @@
 CONFIG_SPL_SERIAL_SUPPORT=y
 CONFIG_SPL=y
 CONFIG_MICRO_SUPPORT_CARD=y
+CONFIG_SYS_LOAD_ADDR=0x85000000
 # CONFIG_ARCH_FIXUP_FDT_MEMORY is not set
 CONFIG_BOOTCOMMAND="run ${bootdev}script; run ${bootdev}boot"
 CONFIG_USE_PREBOOT=y