D5828: fix plasma-frameworks build without kwayland

[David Faure]

dfaure added a reviewer: davidedmundson.

REPOSITORY
  R242 Plasma Framework (Library)

REVISION DETAIL
  https://phabricator.kde.org/D5828

To: winterz, mart, davidedmundson
Cc: dfaure, asturmlechner, apol, #frameworks