rockchip: video: Correct HDMI data source selection

This code currently always selects the second source. It only worked
because both sources are set up.

With the change to only init video devices that are present in the stdout
environment variable, this fails. Fix it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/video/rockchip/rk_hdmi.c b/drivers/video/rockchip/rk_hdmi.c
index 7976c5e..72142dc 100644
--- a/drivers/video/rockchip/rk_hdmi.c
+++ b/drivers/video/rockchip/rk_hdmi.c
@@ -899,7 +899,8 @@
 	rk_setreg(&priv->grf->soc_con6, 1 << 15);
 
 	/* hdmi data from vop id */
-	rk_setreg(&priv->grf->soc_con6, (vop_id == 1) ? (1 << 4) : (1 << 4));
+	rk_clrsetreg(&priv->grf->soc_con6, 1 << 4,
+		     (vop_id == 1) ? (1 << 4) : 0);
 
 	ret = hdmi_wait_for_hpd(priv->regs);
 	if (ret < 0) {