Currently, the planner just pops the first available drm plane and if that can't be used for the DrmHwcLayer it just returns error.
This proposes a slighlty smarter way to do that by trying to see if any of the DrmPlane can be used for the DrmHwcLayer in question.
More, if the drm_plane doesn't have a fix zorder then we could re-add him to the list of unused planes, so it could be used for hosting other less demanding DrmHwcLayers.
Signed-off-by: Alexandru Gheorghe alexandru-cosmin.gheorghe@arm.com