configs/imx6ulevk: Use ext4 as filesystem type

Extend the filesystem type to ext4.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

board/freescale/imx6ulevk/genimage.cfg

@@ -4,7 +4,7 @@
 # * the microSD card must have 1 kB free space at the beginning,
 # * U-Boot is dumped as is,
 # * a FAT partition at offset 8 MB is containing zImage and dtbs,
-# * a single root filesystem partition is required (Ext2 in this case).
+# * a single root filesystem partition is required (Ext4 in this case).
 #
 
 image boot.vfat {
@@ -36,6 +36,6 @@ image sdcard.img {
 
   partition rootfs {
     partition-type = 0x83
-    image = "rootfs.ext2"
+    image = "rootfs.ext4"
   }
 }

configs/freescale_imx6ulevk_defconfig

@@ -33,3 +33,4 @@ BR2_PACKAGE_HOST_MTOOLS=y
 # filesystem / image
 BR2_ROOTFS_POST_IMAGE_SCRIPT="board/freescale/imx6ulevk/post-image.sh"
 BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_4=y