In case of early initialisation errors and on platforms that do not use
the DPU controller, the deinitilisation code can be called with the kms
pointer set to NULL.

Fixes: 98659487 ("drm/msm: add support to take dpu snapshot")
Cc: stable@vger.kernel.org      # 5.14
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/525099/
Link: https://lore.kernel.org/r/20230306100722.28485-4-johan+linaro@kernel.orgSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>