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/stm32mp15_trusted_defconfig b/configs/stm32mp15_trusted_defconfig
index 2e2f0c7..04564e2 100644
--- a/configs/stm32mp15_trusted_defconfig
+++ b/configs/stm32mp15_trusted_defconfig
@@ -14,6 +14,7 @@
 CONFIG_ENV_OFFSET_REDUND=0x2C0000
 CONFIG_TYPEC_STUSB160X=y
 CONFIG_DISTRO_DEFAULTS=y
+CONFIG_SYS_LOAD_ADDR=0xc2000000
 CONFIG_FIT=y
 CONFIG_BOOTDELAY=1
 CONFIG_BOOTCOMMAND="run bootcmd_stm32mp"