stm32f429-discovery: Use ttyS0 as the console device

Mainline kernel will be using this device name as well.

Signed-off-by: Kamil Lulko <rev13@wp.pl>
diff --git a/include/configs/stm32f429-discovery.h b/include/configs/stm32f429-discovery.h
index 1b4fd21..8169cac 100644
--- a/include/configs/stm32f429-discovery.h
+++ b/include/configs/stm32f429-discovery.h
@@ -80,7 +80,7 @@
 
 #define CONFIG_BAUDRATE			115200
 #define CONFIG_BOOTARGS							\
-	"console=ttystm0,115200 earlyprintk consoleblank=0 ignore_loglevel"
+	"console=ttyS0,115200 earlyprintk consoleblank=0 ignore_loglevel"
 #define CONFIG_BOOTCOMMAND						\
 	"run bootcmd_romfs"