loongson/pypi: links for gtimer

loongson/mirror gtimer-1.0.0b5.tar.gz
loongson/mirror gtimer-1.0.0b4.tar.gz
loongson/mirror gtimer-1.0.0b3.tar.gz
loongson/mirror gtimer-1.0.0b2.tar.gz
loongson/mirror gtimer-1.0.0b1.tar.gz
loongson/mirror gtimer-1.0.0b0.tar.gz