[llvm] [LoongArch] Add processor models la64v1.0 and la64v1.1 (PR #110211)

[via llvm-commits]

heiher wrote:

> BTW, what are the plans for adding `-march=la64v1.{0,1}` eventually for feature parity with GCC?

https://github.com/llvm/llvm-project/pull/100057

https://github.com/llvm/llvm-project/pull/110211