Current stable version of libseccomp (2.1.1) only supports i386 and
x86_64 archs correctly. This patch limits the usage of the syscall
filter for those archs and updates to the correct last version of
libseccomp.

This patch also fixes the bug:
https://bugs.launchpad.net/qemu/+bug/1363641



Signed-off-by: Eduardo Otubo <eduardo.otubo@profitbricks.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Paul Moore <pmoore@redhat.com>