There is a third party extension to which will enable the Frippery panel favourites ( shown in pic below ) available from: https://extensions.gnome.org/extension/4/panel-favorites/ this will put icons for your favourites in to the top panel and works with the version of GNOME Shell in SLED 12. As with any third party extension its worth checking our guidance page before enabling: http://www2.warwick.ac.uk/services/its/servicessupport/computers/linuxworkstationguide/faqsandtips/gnomeshellextensions