Bump buildroot to version 2017-02

TG-3 #closed

bsp/buildroot/board/wandboard/genimage.cfg

@@ -2,7 +2,7 @@
 #
 # The SD card must have at least 1 MB free at the beginning.
 # U-Boot and its environment are dumped as is.
-# A single root filesystem partition is required (Ext2 in this case).
+# A single root filesystem partition is required (Ext4 in this case).
 #
 # For details about the layout, see:
 # http://wiki.wandboard.org/index.php/Boot-process
@@ -23,16 +23,9 @@ image sdcard.img {
     offset = 70656
   }
 
-  partition u-boot-env {
-    in-partition-table = "no"
-    image = "uboot-env.bin"
-    offset = 393216
-    size = 8192
-  }
-
   partition rootfs {
     partition-type = 0x83
-    image = "rootfs.ext2"
+    image = "rootfs.ext4"
     size = 512M
   }
 }