drm: xlnx: fix spelling mistake "failes" -> "failed"

There is a spelling mistake in a dev_dbg messages. Fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hyun Kwon <hyun.kwon@xilinx.com>
Signed-off-by: Hyun Kwon <hyun.kwon@xilinx.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200724111258.14762-1-colin.king@canonical.com

drivers/gpu/drm/xlnx/zynqmp_dp.c

@@ -1308,7 +1308,7 @@ zynqmp_dp_connector_detect(struct drm_connector *connector, bool force)
 		ret = drm_dp_dpcd_read(&dp->aux, 0x0, dp->dpcd,
 				       sizeof(dp->dpcd));
 		if (ret < 0) {
-			dev_dbg(dp->dev, "DPCD read failes");
+			dev_dbg(dp->dev, "DPCD read failed");
 			goto disconnected;
 		}