sunxi: Mele_M5_defconfig: Drop non existing STATUSLED setting

And also remove it from scripts/config_whitelist.txt as the
Mele_M5_defconfig was the only one defining it.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
Reviewed-by: Jagan Teki <jagan@openedev.com>