ext4: fix calculating inode blkcount for non-512 blocksize filesystems

ext4: fix calculating inode blkcount for non-512 blocksize filesystems

The block count entry in the EXT4 filesystem disk structures uses
standard 512-bytes units for most of the typical files. The only
exception are HUGE files, which use the filesystem block size, but those
are not supported by uboot's EXT4 implementation anyway. This patch fixes
the EXT4 code to use proper unit count for inode block count. This fixes
errors reported by fsck.ext4 on disks with non-standard (i.e. 4KiB, in
case of new flash drives) PHYSICAL block size after using 'ext4write'
uboot's command.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>