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/p2371-0000_defconfig b/configs/p2371-0000_defconfig
index 039293f..d3d14bf 100644
--- a/configs/p2371-0000_defconfig
+++ b/configs/p2371-0000_defconfig
@@ -6,6 +6,7 @@
 CONFIG_ENV_OFFSET=0xFFFFE000
 CONFIG_DEFAULT_DEVICE_TREE="tegra210-p2371-0000"
 CONFIG_TEGRA210=y
+CONFIG_SYS_LOAD_ADDR=0x80080000
 CONFIG_OF_SYSTEM_SETUP=y
 CONFIG_CONSOLE_MUX=y
 CONFIG_SYS_STDIO_DEREGISTER=y