mx6sabre: Select CMD_EXT4 options

Add EXT4 support.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Otavio Salvador <otavio@ossystems.com.br>
diff --git a/include/configs/mx6sabre_common.h b/include/configs/mx6sabre_common.h
index c3f1b35..f0e37f0 100644
--- a/include/configs/mx6sabre_common.h
+++ b/include/configs/mx6sabre_common.h
@@ -53,6 +53,8 @@
 #define CONFIG_GENERIC_MMC
 #define CONFIG_BOUNCE_BUFFER
 #define CONFIG_CMD_EXT2
+#define CONFIG_CMD_EXT4
+#define CONFIG_CMD_EXT4_WRITE
 #define CONFIG_CMD_FAT
 #define CONFIG_DOS_PARTITION