drm/msm: Update compatible strings for mdp

Create distinct compatible strings for mdp4 and mdp5. Keep "qcom,mdss_mdp"
as is to support downstream kernels.
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/msm_drv.c

@@ -1092,8 +1092,10 @@ static const struct platform_device_id msm_id[] = {
 };
 
 static const struct of_device_id dt_match[] = {
-	{ .compatible = "qcom,mdp", .data = (void *) 4 },     /* mdp4 */
-	{ .compatible = "qcom,mdss_mdp", .data = (void *) 5 }, /* mdp5 */
+	{ .compatible = "qcom,mdp4", .data = (void *) 4 },	/* mdp4 */
+	{ .compatible = "qcom,mdp5", .data = (void *) 5 },	/* mdp5 */
+	/* to support downstream DT files */
+	{ .compatible = "qcom,mdss_mdp", .data = (void *) 5 },  /* mdp5 */
 	{}
 };
 MODULE_DEVICE_TABLE(of, dt_match);