loongson/pypi: links for pmath

loongson/mirror pmath-0.3.tar.gz
loongson/mirror pmath-0.3.linux-x86_64.tar.gz
loongson/mirror pmath-0.2.tar.gz
loongson/mirror pmath-0.2.linux-x86_64.tar.gz
loongson/mirror pmath-0.1.tar.gz
loongson/mirror pmath-0.1.linux-x86_64.tar.gz