auto-package-utils.oeclass: add AUTO_PACKAGE_UTILS_DOC_PACKAGES to PACKAGES
auto-package-utils.oeclass: add AUTO_PACKAGE_UTILS_DOC_PACKAGES to PACKAGES

We automatically populate a FILES variable for the doc packages, but
that doc package name never get added to the PACKAGES list, so the man
pages end up in the main package.

sknsean/core,sknsean/core,sknsean/core,sknsean/core,sknsean/core