drm/msm/mdp4: Fix refcount leak in mdp4_modeset_init_intf

drm/msm/mdp4: Fix refcount leak in mdp4_modeset_init_intf

of_graph_get_remote_node() returns remote device node pointer with
refcount incremented, we should use of_node_put() on it
when not need anymore.
Add missing of_node_put() to avoid refcount leak.

Fixes: 5a2ac032f13c ("drm: convert drivers to use of_graph_get_remote_node")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/488473/
Link: https://lore.kernel.org/r/20220607110841.53889-1-linmq006@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>