Copy src/LICENSE verbatim from radxa-pkg/aic8800 commit
969601fd69b5c33f965558c9e90633067733e8c1 and document its provenance.
Upstream copyright metadata assigns GPL-2 to driver sources and the
same license to driver patches; GPL-3+ applies to Radxa packaging.
Refs #101.
Validation: byte-for-byte upstream license comparison and git diff --check.
