docs/zh_CN: add sysfs-pci trnaslation

Translate .../PCI/sysfs-pci.rst into Chinese.

Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/0c18e5eadaf47ec2befcf38e515c244cd700e13f.1639224005.git.siyanteng@loongson.cn


Signed-off-by: Jonathan Corbet <corbet@lwn.net>