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

[via llvm-commits]

heiher wrote:

CLOSE: Internal reviewers believe that this change will make the `-mtune` value in Clang inconsistent with the [`la-toolchain-convention`](https://github.com/loongson/la-toolchain-conventions?tab=readme-ov-file#list).

The changes to `generic` will be addressed in another PR.

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