loongson/pypi: links for cnexchcal

loongson/mirror cnexchcal-0.3.1-py3-none-any.whl
loongson/mirror cnexchcal-0.3.0-py3-none-any.whl
loongson/mirror cnexchcal-0.2.1-py3-none-any.whl
loongson/mirror cnexchcal-0.2.0-py3-none-any.whl