Functionality remains largely the same as before.

Note that the retry loops and native reply handling all moved into the
core drm helper functions now.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
[danvet: Fix up the stray ; Rodrigo spotted in his review and add a
note to the commit message to answer Rodrigo's question in his review.]
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>