drm/mediatek: Fix child node refcount handling in early exit

Early exits (goto, break, return) from for_each_child_of_node() required
an explicit call to of_node_put(), which was not introduced with the
break if cnt == MAX_CRTC.

Add the missing of_node_put() before the break.

Cc: stable@vger.kernel.org
Fixes: d761b945 ("drm/mediatek: Add cnt checking for coverity issue")

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20241011-mtk_drm_drv_memleak-v1-1-2b40c74c8d75@gmail.com/


Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>