Application background is incorrect if app locked to landscape.

Application background is incorrect if app locked to landscape.

If application orientation has been locked to landscape and application
is started out while device orientation is portrait, QS60Style draws
the QPalette::background like device would be in landscape. Style
is incorrectly following device orientation, when it should follow
application orientation.

As a fix, style follows now application orientation. As a bonus,
unnecessary fullscreen QPixmap creation is avoided when rotating the
device.

Task-number: QTBUG-16816
Reviewed-by: Jani Hautakangas
(cherry picked from commit 54313b3ba81c276cf06c40c2420b1ff1f30e64c3)