package: Fix license exclusion packaging errors

package: Fix license exclusion packaging errors

Currently the license exclusion code removes packages from PACKAGES
pre population of the package directories. This means that the FILES
entries for some packages are not seen and invariably results in
packaging errors.

Instead, remove the packages from PACKAGES post population of the packages
so the usual FILES entries work as expected but the file are not placed
into any packages and no packages containing embargoed licenses are generated.

This avoids errors from gcc-runtime with GPLv3 exclusion like:

ERROR: QA Issue: gcc-runtime: Files/directories were installed but not shipped in any package:
  /usr/share
  /usr/src
  /usr/share/gcc-4.9.2
  /usr/share/gcc-4.9.2/python
Please set FILES such that these items are packaged. Alternatively if they are unneeded, avoid installing them or delete them within do_install. [installed-vs-shipped]

(From OE-Core rev: 09c3d648c95fe88197c15d656bda1c9303aa2079)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>