Documentation:Update Documentation/zh_CN/arm64/booting.txt

This is a update of Chinese documentation: Documentation/zh_CN/arm64/booting.txt

It is based on the modifications of Documentation/arm64/booting.txt in submission:
"a7f8de16".

Signed-off-by: Fu Wei <wefu@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>