If the view is not mapped, we do not need to update its
properties. We can use ivi_view_is_mapped() function to
check it.

Also we don't need to call weston_view_damage_below()
for weston_views, which were in the scenegraph. Because
we are calling weston_view_unmap for views of unmapped
ivi_views in build_view_list() function

Signed-off-by: Emre Ucan <eucan@de.adit-jv.com>