mvebu: fixup Turris Omnia U-Boot environment

mvebu: fixup Turris Omnia U-Boot environment

Fixup dfa357a3de "mvebu: base-files: Update Turris Omnia U-Boot
environment" which should have included this file as well.

By rebasing the initial patch this file somehow disappeared.

Signed-off-by: Klaus Kudielka <[email protected]>
Reviewed-by: Tomasz Maciej Nowak <[email protected]>
Tested-by: W. Michael Petullo <[email protected]> (Turris Omnia "2020")
Tested-by: Klaus Kudielka <[email protected]> (Turris Omnia)
[explain fixup in commit message]
Signed-off-by: Paul Spooren <[email protected]>