video: Factor out vidconsole_put_string()

Pull the vidconsole_put_string() function from DM tests, make it
available to e.g. boards that want to display information on the
LCD on boot.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
diff --git a/drivers/video/vidconsole-uclass.c b/drivers/video/vidconsole-uclass.c
index c31303b..af88588 100644
--- a/drivers/video/vidconsole-uclass.c
+++ b/drivers/video/vidconsole-uclass.c
@@ -529,6 +529,20 @@
 	return 0;
 }
 
+int vidconsole_put_string(struct udevice *dev, const char *str)
+{
+	const char *s;
+	int ret;
+
+	for (s = str; *s; s++) {
+		ret = vidconsole_put_char(dev, *s);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 static void vidconsole_putc(struct stdio_dev *sdev, const char ch)
 {
 	struct udevice *dev = sdev->priv;
@@ -541,8 +555,7 @@
 {
 	struct udevice *dev = sdev->priv;
 
-	while (*s)
-		vidconsole_put_char(dev, *s++);
+	vidconsole_put_string(dev, s);
 	video_sync(dev->parent, false);
 }