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/cei-tk1-som_defconfig b/configs/cei-tk1-som_defconfig
index 077324a..2ac9076 100644
--- a/configs/cei-tk1-som_defconfig
+++ b/configs/cei-tk1-som_defconfig
@@ -9,6 +9,7 @@
 CONFIG_TEGRA124=y
 CONFIG_TARGET_CEI_TK1_SOM=y
 CONFIG_ARMV7_PSCI_0_1=y
+CONFIG_SYS_LOAD_ADDR=0x81000000
 CONFIG_OF_SYSTEM_SETUP=y
 CONFIG_CONSOLE_MUX=y
 CONFIG_SYS_STDIO_DEREGISTER=y