drm/tegra: Shutdown on driver unbind

drm/tegra: Shutdown on driver unbind

BugLink: http://bugs.launchpad.net/bugs/1786352
[ Upstream commit 192b4af6cd28cdad9b42fd79c21a90a2aeb0bec7 ]

Since commit 846c7dfc1193 ("drm/atomic: Try to preserve the crtc enabled
state in drm_atomic_remove_fb, v2."), removing the last framebuffer will
no longer disable the corresponding pipeline, which causes the KMS core
to complain about leaked connectors on driver unbind.

Fix this by calling drm_atomic_helper_shutdown() on driver unbind, which
will cause all display pipelines to be shut down and therefore drop the
extra references on the connectors.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>