ARM: socfpga_defconfig: enable support for large block devices

Enable CONFIG_LBDAF, which is required by ext4 fs. This option could
handle both ext3 and ext4, with ext4 requires this option to be enabled,
otherwise the filesystem is mounted RO mode.

Since the LBDAF is enabled by default for 32-bit systems, simply
removing the current "not set" entry enables the support.

Signed-off-by: Andrey Zhizhikin <andrey.z@gmail.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>