drm/gem: create drm_gem_dumb_destroy

All the gem based kms drivers really want the same function to
destroy a dumb framebuffer backing storage object.

So give it to them and roll it out in all drivers.

This still leaves the option open for kms drivers which don't use GEM
for backing storage, but it does decently simplify matters for gem
drivers.

Acked-by: Inki Dae <inki.dae@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Intel Graphics Development <intel-gfx@lists.freedesktop.org>
Cc: Ben Skeggs <skeggsb@gmail.com>
Reviwed-by: Rob Clark <robdclark@gmail.com>
Cc: Alex Deucher <alexdeucher@gmail.com>
Acked-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index 40b71da..14801c2 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -519,7 +519,7 @@
 	.gem_vm_ops         = &drm_gem_cma_vm_ops,
 	.dumb_create        = drm_gem_cma_dumb_create,
 	.dumb_map_offset    = drm_gem_cma_dumb_map_offset,
-	.dumb_destroy       = drm_gem_cma_dumb_destroy,
+	.dumb_destroy       = drm_gem_dumb_destroy,
 #ifdef CONFIG_DEBUG_FS
 	.debugfs_init       = tilcdc_debugfs_init,
 	.debugfs_cleanup    = tilcdc_debugfs_cleanup,