ext4: add support for filesystems without JOURNAL
JOURNAL is optional for EXT4 (and EXT3) filesystems, so add support for
skipping it. This fixes corrupting EXT4 volumes without JOURNAL after
using uboot's 'ext4write' command.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>