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/p3450-0000_defconfig b/configs/p3450-0000_defconfig
index 9f9a5ed..3e84e86 100644
--- a/configs/p3450-0000_defconfig
+++ b/configs/p3450-0000_defconfig
@@ -8,6 +8,7 @@
 CONFIG_DEFAULT_DEVICE_TREE="tegra210-p3450-0000"
 CONFIG_TEGRA210=y
 CONFIG_TARGET_P3450_0000=y
+CONFIG_SYS_LOAD_ADDR=0x80080000
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_OF_SYSTEM_SETUP=y
 CONFIG_CONSOLE_MUX=y