drm/sun4i: Unbind components before releasing DRM and memory

Our components may still be using the DRM device driver (if only to
access our driver's private data), so make sure to unbind them before
the final drm_dev_put.

Also release our reserved memory after component unbind instead of
before to match reverse creation order.

Fixes: f5a9ed86 ("drm/sun4i: Fix component unbinding and component master deletion")
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190424090413.6918-1-paul.kocialkowski@bootlin.com