video: Add a function to clear the display

Move the code from the 'cls' command into the console file, so it can
be called from elsewhere.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/cls.c b/cmd/cls.c
index 1125a3f..80d0558 100644
--- a/cmd/cls.c
+++ b/cmd/cls.c
@@ -7,33 +7,14 @@
  */
 #include <common.h>
 #include <command.h>
+#include <console.h>
 #include <dm.h>
-#include <video_console.h>
-
-#define CSI "\x1b["
 
 static int do_video_clear(struct cmd_tbl *cmdtp, int flag, int argc,
 			  char *const argv[])
 {
-	__maybe_unused struct udevice *dev;
-
-	/*
-	 * Send clear screen and home
-	 *
-	 * FIXME(Heinrich Schuchardt <xypron.glpk@gmx.de>): This should go
-	 * through an API and only be written to serial terminals, not video
-	 * displays
-	 */
-	printf(CSI "2J" CSI "1;1H");
-	if (IS_ENABLED(CONFIG_VIDEO_ANSI))
-		return 0;
-
-	if (IS_ENABLED(CONFIG_VIDEO)) {
-		if (uclass_first_device_err(UCLASS_VIDEO_CONSOLE, &dev))
-			return CMD_RET_FAILURE;
-		if (vidconsole_clear_and_reset(dev))
-			return CMD_RET_FAILURE;
-	}
+	if (console_clear())
+		return CMD_RET_FAILURE;
 
 	return CMD_RET_SUCCESS;
 }