mxs: Linux uses ttyAMA0 as DUART

Replace use of ttyAM0 with ttyAMA0 as default serial console.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
diff --git a/include/configs/m28evk.h b/include/configs/m28evk.h
index 6887171..d34e970 100644
--- a/include/configs/m28evk.h
+++ b/include/configs/m28evk.h
@@ -274,7 +274,7 @@
 #define	CONFIG_SETUP_MEMORY_TAGS
 #define	CONFIG_BOOTDELAY	3
 #define	CONFIG_BOOTFILE		"uImage"
-#define	CONFIG_BOOTARGS		"console=ttyAM0,115200n8 "
+#define	CONFIG_BOOTARGS		"console=ttyAMA0,115200n8 "
 #define	CONFIG_BOOTCOMMAND	"run bootcmd_net"
 #define	CONFIG_LOADADDR		0x42000000
 #define	CONFIG_SYS_LOAD_ADDR	CONFIG_LOADADDR