Reimplement driver.*_data_own variables so that they actually
work for a usecase now -

on Xbox, full teardown/re-initing of D3D context seems to be
error-prone - so by flagging driver.video_data_own to true inside
of the video_init function, we signal later on to the uninit_drivers
function that we DO NOT want to call the free function of this driver
and clean up the handle.

Instead, this driver should properly retain the handle by returning
the pre-existing handle when (for example) driver.video_data is
not NULL. You can see an example of this in xdk/xdk_d3d.cpp.

Overall still a quite clean solution and we will only use this in
extraordinary conditions (like this Xbox one I suppose) - full
teardown/setup will be the goal for all other platforms where we
can be certain that the state can be brought down and up entirely
during runtime without any problems.