TiDB: Add loong64 in Supported CPU arch list

[shawn0915]

Change Request

Please answer the following questions before submitting your issue. Thanks!

1. Describe what you find is inappropriate or missing in the existing docs.

https://docs.pingcap.com/tidb/stable/hardware-and-software-requirements/ only x86_64 / ARM 64 display here.

2. Describe your suggestion or addition.

https://docs.pingcap.com/tidb/stable/release-8.5.2/

TiDB supports compilation and building on the Loongson loong64 architecture

Can we add loong64 into supported cpu arch list?

3. Provide some reference materials (such as documents and websites) if you could.

leave a message in the forum. https://asktug.com/t/topic/1043212