Currently printing and pdf are bounded together. Make compilation
optional by adding it as a feature.

Fix formatting of embedded_linux.pri

Task-number: QTBUG-57731
Task-number: QTBUG-58108
Change-Id: I53a2baea656df0a5b6139365ed06385c9ebc5830
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>