drm/msm/mdp5: use devres-managed allocation for configuration data

drm/msm/mdp5: use devres-managed allocation for configuration data

Use devm_kzalloc to create configuration data structure. This allows us
to remove corresponding kfree and drop mdp5_cfg_destroy() function.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/546156/
Link: https://lore.kernel.org/r/20230708010407.3871346-3-dmitry.baryshkov@linaro.org