(platform) egl-dri work towards rendernode support
(platform) fixed segfault in dri regression

This re-introduces the issue where history will 'flicker', particularly
in static/non-initialized contents e.g. multi-buffered rendering as the
current FB is drawn due to dirty video pipeline, next frame is not dirty
but BB will swap anyhow. This should be fixed in a more stable way when
rendernodes / multi-head output is working properly.