build-many-glibcs.py: Add s390 --disable-multi-arch / multi-arch configurations.

This patch adds some --disable-multi-arch variants for s390x.

As the used IFUNC variants and __GI symbols depend on the used
gcc -march=cpu-level, there are multiple new configurations.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>