vision2: do not overwrite the console

On this board, the console is always set to the serial line.
Do not allow to overwrite it when video is enabled.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>

board/ttcontrol/vision2/vision2.c

@@ -674,11 +674,18 @@ int board_late_init(void)
 	udelay(2000);
 #endif
 
-	setenv("stdout", "serial");
-
 	return 0;
 }
 
+/*
+ * Do not overwrite the console
+ * Use always serial for U-Boot console
+ */
+int overwrite_console(void)
+{
+	return 1;
+}
+
 int checkboard(void)
 {
 	puts("Board: TTControl Vision II CPU V\n");

include/configs/vision2.h

@@ -214,6 +214,8 @@
 #define CONFIG_VIDEO_IPUV3
 #define CONFIG_CFB_CONSOLE
 #define CONFIG_VGA_AS_SINGLE_DEVICE
+#define CONFIG_SYS_CONSOLE_IS_IN_ENV
+#define CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
 #define CONFIG_VIDEO_BMP_RLE8
 #define CONFIG_SPLASH_SCREEN
 #define CONFIG_CMD_BMP