Save firmware if known in the profile.

Summary: If the user makes a new profile and does not set a firmware plugin. The auto detect routine is run to find out what firmware the machines uses. Now if that happens after we are connected our AtCoreInstanceWidget will save the name of the loaded firmware into the profile. This will make Atelier connect faster on future connections because it will not need to wait for the firmware auto detect routine to finish

Reviewers: laysrodrigues, tcanabrava, patrickelectric

Reviewed By: laysrodrigues, patrickelectric

Subscribers: Atelier: General Development

Tags: Atelier: General Development

Differential Revision: https://phabricator.kde.org/D18003