configs: Re-run migrations

As the CI test for stopping platforms from being merged that were
defining symbols that had Kconfig entries, a small number of symbols
needed to be migrated again.  Do so, and catch two cases the README
should also have been updated but was not.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/imx8mp_rsb3720a1_4G_defconfig b/configs/imx8mp_rsb3720a1_4G_defconfig
index 90e1c15..04d3634 100644
--- a/configs/imx8mp_rsb3720a1_4G_defconfig
+++ b/configs/imx8mp_rsb3720a1_4G_defconfig
@@ -22,9 +22,12 @@
 CONFIG_SPL_SERIAL=y
 CONFIG_SPL_DRIVERS_MISC=y
 CONFIG_SPL=y
+CONFIG_IMX_BOOTAUX=y
 CONFIG_SPL_IMX_ROMAPI_LOADADDR=0x48000000
 CONFIG_DEFAULT_DEVICE_TREE="imx8mp-rsb3720-a1"
 CONFIG_DISTRO_DEFAULTS=y
+CONFIG_REMAKE_ELF=y
+CONFIG_SYS_LOAD_ADDR=0x40480000
 CONFIG_FIT=y
 CONFIG_FIT_EXTERNAL_OFFSET=0x3000
 CONFIG_FIT_SIGNATURE=y