Convert CONFIG_STANDALONE_LOAD_ADDR to Kconfig

This converts the following to Kconfig:
   CONFIG_STANDALONE_LOAD_ADDR

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/display5_defconfig b/configs/display5_defconfig
index dbd917b..c46a0a0 100644
--- a/configs/display5_defconfig
+++ b/configs/display5_defconfig
@@ -30,6 +30,7 @@
 CONFIG_SPL_SPI_FLASH_SUPPORT=y
 CONFIG_SPL_SPI=y
 CONFIG_SYS_MONITOR_LEN=409600
+CONFIG_STANDALONE_LOAD_ADDR=0x10001000
 CONFIG_FIT=y
 CONFIG_SPL_LOAD_FIT=y
 # CONFIG_USE_SPL_FIT_GENERATOR is not set