lib.licenses.asl20-llvm: replace with separate llvm-exception

This essentially reverts 7ce8e7c4cf90492a631e96bcfe70724104914381

asl20-llvm does not produce a valid SPDX ID, it produces a valid SPDX
Expression. However, this is not what the spdxId field promises.

This is relevant because we cannot produce valid SBOMs (e.g. CycloneDX)
using this field as the schemas for these SBOMs check that the IDs are
valid.

This change leaves us with consistently valid SPDX IDs at the cost
of slightly less convenience.

0 files changed, 0 insertions, 0 deletions