CUDA: Restore support for non-"all" CUDA_ARCHITECTURES with nvcc 11.5+

Since commit 8f64df0a7c (CUDA: Generic all and all-major support,
2021-12-19, v3.23.0-rc1~23^2), setting `CUDA_ARCHITECTURES` to a value
other than `all` or `all-major` is ignored with NVCC 11.5+.  Fix the
logic to return early only when actually using an "all" value.

Fixes: #23243