arm: ls1021a: Add CONFIG_DOS_PARTITION and CONFIG_CMD_FAT support

This patch will fix the bug that the partitions on the SD card could
not be accessed and add the support for the FAT fs.

Signed-off-by: Alison Wang <alison.wang@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/include/configs/ls1021atwr.h b/include/configs/ls1021atwr.h
index 9a54322..aa9ec72 100644
--- a/include/configs/ls1021atwr.h
+++ b/include/configs/ls1021atwr.h
@@ -212,6 +212,9 @@
 #define CONFIG_FSL_ESDHC
 #define CONFIG_GENERIC_MMC
 
+#define CONFIG_CMD_FAT
+#define CONFIG_DOS_PARTITION
+
 /*
  * Video
  */