Add the directory to the file list so that it gets deleted when the RPM gets
uninstalled.

Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
In case dracut modules live in a different place in different distros go find it
based on where dracut-functions script lives.

Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>