package.bbclass: ensure license excluded files aren't packaged

package.bbclass: ensure license excluded files aren't packaged

An excluded package left its files behind, which meant they could end up in
another package instead, meaning we could ship GPLv3 binaries even with GPLv3
in INCOMPATIBLE_LICENSE. Skip the files belonging to the excluded packages to
prevent this from occurring.

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>