arm: am57xx: cl-som-am57x: adjust default env to the installation system

The SD card automatic installation system depends on the default
environment of the previous U-Boot.

Add the missing environment variables.

Signed-off-by: Uri Mashiach <uri.mashiach@compulab.co.il>
Reviewed-by: Tom Rini <trini@konsulko.com>
1 file changed