qmake5: Ensure that the correct qmake is used when building

Signed-off-by: Christian Sørensen <christian.braunersorensen@prevas.dk>
qt4: use archives for downloads, contains all releases

(cherry picked from commit b000be9c205714d97ba6ab30fdb8693e4a910f06)
Signed-off-by: Christian Sørensen <christian.braunersorensen@prevas.dk>
qt-x11: Add missing dependencies for libqtgui

Signed-off-by: Christian Sørensen <christian.braunersorensen@prevas.dk>
qmake: Add endian to the list of QT_CONFIG_FLAGS

Signed-off-by: Christian Sørensen <christian.braunersorensen@prevas.dk>
qmake: fix building sdk:qmake when build host is different from sdk host

The patch ensures that qmake is taken from the native version, and used
in the sdk build.

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