qmake: Rework setting the build/host endians

Signed-off-by: Christian Sørensen <christian.braunersorensen@prevas.dk>
qmake5: Add pkgconfig class and add use flag to build dbus tools

Use flag added: qtdbus. Default disabled.
Note that the same useflag appears in qtbase, so if enabling the useflag
the right tools is build in qmake, and used in qtbase.

Signed-off-by: Christian Sørensen <christian.braunersorensen@prevas.dk>
qtbase: Use local build dbus tools from qmake5

Signed-off-by: Christian Sørensen <christian.braunersorensen@prevas.dk>
qt5: Add packages based on whether the qtexamples use flag is set.

The useflag used were previously used in qtbase, but has now been moved

Signed-off-by: Christian Sørensen <christian.braunersorensen@prevas.dk>
qtbase: Remove qtexamples useflag. Has been moved to qt5.

Signed-off-by: Christian Sørensen <christian.braunersorensen@prevas.dk>