ssu is now handling the repository configurations no need for rpm installations anymore.

ssu vendor data is now part of Nemo MW group. Also ssu is now handling the
repository files itself so we don't need to install rpm's anymore.

Signed-off-by: Marko Saukko <marko.saukko@gmail.com>
Added ssu post script.

This make the repository files to be written during image builds.

Signed-off-by: Marko Saukko <marko.saukko@gmail.com>