phy: samsung,dp-video-phy: deprecate syscon phandle

The DisplayPort phy is actually part of the Power Management Unit system
controller, thus it should be its child, instead of sibling node with
syscon phandle.
Acked-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20230127194057.186458-5-krzysztof.kozlowski@linaro.orgSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

drivers/phy/samsung/phy-exynos-dp-video.c

@@ -83,8 +83,11 @@ static int exynos_dp_video_phy_probe(struct platform_device *pdev)
 	if (!state)
 		return -ENOMEM;
 
-	state->regs = syscon_regmap_lookup_by_phandle(dev->of_node,
-						      "samsung,pmu-syscon");
+	state->regs = syscon_node_to_regmap(dev->parent->of_node);
+	if (IS_ERR(state->regs))
+		/* Backwards compatible way */
+		state->regs = syscon_regmap_lookup_by_phandle(dev->of_node,
+							      "samsung,pmu-syscon");
 	if (IS_ERR(state->regs)) {
 		dev_err(dev, "Failed to lookup PMU regmap\n");
 		return PTR_ERR(state->regs);