UBUNTU: Include nls_cp437 module in virtual for fat

UBUNTU: Include nls_cp437 module in virtual for fat

The virtual flavor only ships whitelisted modules including the fat and
vfat modules, but because it doesn't include any codepage modules
(nls_cp*) FAT support is useless.  Include the default codepage
(nls_cp437) in virtual to allow mounting FAT filesystems.

BugLink: http://bugs.launchpad.net/bugs/732046

Signed-off-by: Loïc Minier <loic.minier@linaro.org>
Acked-by: Andy Whitcroft <andy.whitcroft@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>