arch: x86-32 -- Be able to build 32bit CRIU

After this patch one can run ARCH="ia32" make to build
32bit version on CRIU on 64bit host. Note this is only
build procedure which tuned up, the CRIU itself is not
yet ready to make a checkpoint/restore cycle -- a lot
of additional code is needed and here we rather put
stubs simply to make build procedure run.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>