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/controlcenterdc_defconfig b/configs/controlcenterdc_defconfig
index bb1e095..4d6eac3 100644
--- a/configs/controlcenterdc_defconfig
+++ b/configs/controlcenterdc_defconfig
@@ -19,6 +19,7 @@
 CONFIG_DEBUG_UART=y
 CONFIG_AHCI=y
 CONFIG_OF_BOARD_FIXUP=y
+CONFIG_SYS_LOAD_ADDR=0x800000
 CONFIG_FIT=y
 CONFIG_FIT_SIGNATURE=y
 CONFIG_FIT_VERBOSE=y