llvm: Include llvm-link in minimal (CI) toolchains

This is wanted by kernel-c18n.

pycheribuild/projects/cross/llvm.py

@@ -174,6 +174,7 @@ def setup_config_options(cls, **kwargs):
         "lld",
         "llvm-ar",
         "llvm-cxxfilt",
+        "llvm-link",
         "llvm-mc",
         "llvm-nm",
         "llvm-objcopy",