drm/mediatek: Fix using wrong drm private data to bind mediatek-drm

According to mtk_drm_kms_init(), the all_drm_private array in each
drm private data stores all drm private data in display path order.

In mtk_drm_get_all_drm_priv(), each element in all_drm_priv should have one
display path private data, such as:
all_drm_priv[CRTC_MAIN] should only have main_path data
all_drm_priv[CRTC_EXT] should only have ext_path data
all_drm_priv[CRTC_THIRD] should only have third_path data

So we need to add the length checking for each display path before
assigning their drm private data into all_drm_priv array.

Then the all_drm_private array in each drm private data needs to be
assigned in their display path order.

Fixes: 1ef7ed4 ("drm/mediatek: Modify mediatek-drm for mt8195 multi mmsys support")
Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Tested-by: Fei Shao <fshao@chromium.org>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20231004024013.18956-4-jason-jh.lin@mediatek.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

Author: Jason-JH.Lin

drivers/gpu/drm/mediatek/mtk_drm_drv.c

@@ -352,6 +352,7 @@ static bool mtk_drm_get_all_drm_priv(struct device *dev)
 {
 	struct mtk_drm_private *drm_priv = dev_get_drvdata(dev);
 	struct mtk_drm_private *all_drm_priv[MAX_CRTC];
+	struct mtk_drm_private *temp_drm_priv;
 	struct device_node *phandle = dev->parent->of_node;
 	const struct of_device_id *of_id;
 	struct device_node *node;
@@ -371,11 +372,21 @@ static bool mtk_drm_get_all_drm_priv(struct device *dev)
 			continue;
 
 		drm_dev = device_find_child(&pdev->dev, NULL, mtk_drm_match);
-		if (!drm_dev || !dev_get_drvdata(drm_dev))
+		if (!drm_dev)
 			continue;
 
-		all_drm_priv[cnt] = dev_get_drvdata(drm_dev);
-		if (all_drm_priv[cnt] && all_drm_priv[cnt]->mtk_drm_bound)
+		temp_drm_priv = dev_get_drvdata(drm_dev);
+		if (!temp_drm_priv)
+			continue;
+
+		if (temp_drm_priv->data->main_len)
+			all_drm_priv[CRTC_MAIN] = temp_drm_priv;
+		else if (temp_drm_priv->data->ext_len)
+			all_drm_priv[CRTC_EXT] = temp_drm_priv;
+		else if (temp_drm_priv->data->third_len)
+			all_drm_priv[CRTC_THIRD] = temp_drm_priv;
+
+		if (temp_drm_priv->mtk_drm_bound)
 			cnt++;
 
 		if (cnt == MAX_CRTC)