Add enablefont and disablefont icon for kfontinst KCM
Summary:
Reviewers: Breeze, ndavis, GB_2
Reviewed By: Breeze, ndavis, GB_2
Subscribers: GB_2, ndavis, broulik, ngraham, kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D23942