[libclc] [libclc] Only check the triple architecture for libclc (PR #194149)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

> Sorry, could you give me a hint how to determine all the values we should be building libclc for now? Previously I would just use `LIBCLC_TARGETS_ALL`.

We should probably have a cache file, there were a lot of changes recently.

https://github.com/llvm/llvm-project/pull/194149