docs/zh_CN: add pci-iov-howto translation

Translate .../PCI/pci-iov-howto.rst into Chinese.

Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/4c67e3a0ab6c8fe12b97adb924f079d7425d40c5.1636683482.git.siyanteng@loongson.cn


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