This update for sddm fixes the following issues:

- Add SLE branding package for PackageHub (boo#1101297)

- Change the Supplements of branding packages, so they get installed
when sddm and the respective branding package is installed. Also
added a Supplements to sddm so it gets recommended when
plasma5-workspace is installed.

- Provide a sddm-branding-SLE package with correct dependencies,
together with sddm-branding-openSUSE (boo#1025387, boo#1069396)