drm/mediatek: Fix device passed to cmdq

drm device is now probed from mmsys. We need to use mmsys device to get gce
nodes. Fix following errors:

[    0.740068] mediatek-drm mediatek-drm.1.auto: error -2 can't parse gce-client-reg property (0)
[    0.748721] mediatek-drm mediatek-drm.1.auto: error -2 can't parse gce-client-reg property (0)
...
[    2.659645] mediatek-drm mediatek-drm.1.auto: failed to request channel
[    2.666270] mediatek-drm mediatek-drm.1.auto: failed to request channel

Fixes: 667c7692 ("soc / drm: mediatek: Fix mediatek-drm device probing")
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

drivers/gpu/drm/mediatek/mtk_drm_crtc.c

@@ -831,7 +831,8 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
 	mtk_crtc->cmdq_client =
-			cmdq_mbox_create(dev, drm_crtc_index(&mtk_crtc->base),
+			cmdq_mbox_create(mtk_crtc->mmsys_dev,
+					 drm_crtc_index(&mtk_crtc->base),
 					 2000);
 	if (IS_ERR(mtk_crtc->cmdq_client)) {
 		dev_dbg(dev, "mtk_crtc %d failed to create mailbox client, writing register by CPU now\n",

drivers/gpu/drm/mediatek/mtk_drm_drv.c

@@ -514,7 +514,8 @@ static int mtk_drm_probe(struct platform_device *pdev)
 				goto err_node;
 			}
 
-			ret = mtk_ddp_comp_init(dev, node, comp, comp_id, NULL);
+			ret = mtk_ddp_comp_init(dev->parent, node, comp,
+						comp_id, NULL);
 			if (ret) {
 				of_node_put(node);
 				goto err_node;