samples: add new mipsel-sde-elf sample.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
[yann.morin.1998@anciens.enib.fr: add pointer to ML thread]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

# Compute s390-specific values

CT_DoArchTupleValues() {

    # That's the only thing to override

    if [ "${CT_ARCH_64}" = "y" ]; then

        CT_TARGET_ARCH="s390x"

    fi

}