loongson/mirror: links for libsvm

loongson/mirror libsvm-3.23.0.4.tar.gz
loongson/mirror libsvm-3.23.0.3.tar.gz
loongson/mirror libsvm-3.23.0.2.tar.gz
loongson/mirror libsvm-3.23.0.1.tar.gz
loongson/mirror libsvm-3.23.0.tar.gz
loongson/mirror libsvm-3.23.0-a1.tar.gz