rockchip: video: Use ofnode_decode_display_timing() to parse timing

Use ofnode_decode_display_timing() instead of
fdtdec_decode_display_timing() to parse display timing, so that we can
support live DT.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/video/rockchip/rk_lvds.c b/drivers/video/rockchip/rk_lvds.c
index 79e24ba..404af7e 100644
--- a/drivers/video/rockchip/rk_lvds.c
+++ b/drivers/video/rockchip/rk_lvds.c
@@ -161,8 +161,7 @@
 
 int rk_lvds_read_timing(struct udevice *dev, struct display_timing *timing)
 {
-	if (fdtdec_decode_display_timing
-	    (gd->fdt_blob, dev_of_offset(dev), 0, timing)) {
+	if (ofnode_decode_display_timing(dev_ofnode(dev), 0, timing)) {
 		debug("%s: Failed to decode display timing\n", __func__);
 		return -EINVAL;
 	}
diff --git a/drivers/video/rockchip/rk_mipi.c b/drivers/video/rockchip/rk_mipi.c
index f9280e8..a77bdfd 100644
--- a/drivers/video/rockchip/rk_mipi.c
+++ b/drivers/video/rockchip/rk_mipi.c
@@ -29,8 +29,7 @@
 {
 	int ret;
 
-	ret = fdtdec_decode_display_timing(gd->fdt_blob, dev_of_offset(dev),
-					 0, timing);
+	ret = ofnode_decode_display_timing(dev_ofnode(dev), 0, timing);
 	if (ret) {
 		debug("%s: Failed to decode display timing (ret=%d)\n",
 		      __func__, ret);