drm/vc4: Continue the switch to drm_*_put() helpers

Use drm_*_get() and drm_*_put() helpers instead of drm_*_reference()
and drm_*_unreference() helpers.

drm_*_reference() and drm_*_unreference() functions are just
compatibility alias for drm_*_get() and drm_*_put() and should not be
used by new code. So convert all users of compatibility functions to
use the new APIs.

Generated by: scripts/coccinelle/api/drm-get-put.cocci

v2: Tweak commit summary to distinguish it from the previous commit
    covering everything but the new bo_label ioctl (by anholt).
Signed-off-by: Cihangir Akturk <cakturk@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/1502454794-28558-25-git-send-email-cakturk@gmail.comReviewed-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/vc4/vc4_bo.c

@@ -830,7 +830,7 @@ int vc4_label_bo_ioctl(struct drm_device *dev, void *data,
 		ret = -ENOMEM;
 	mutex_unlock(&vc4->bo_lock);
 
-	drm_gem_object_unreference_unlocked(gem_obj);
+	drm_gem_object_put_unlocked(gem_obj);
 
 	return ret;
 }