seccomp: libseccomp version varying according to arch

Libseccomp dependency was mandating version 2.2.0 on all architectures
and this was causing configure and virt-test to break on non-updates
distros. This patch works-around it and give a more flexible way to
check the version, giving more time for other distros to update
libseccomp version.

Signed-off-by: Eduardo Otubo <eduardo.otubo@profitbricks.com>
Reported-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Tested-by: Juan Quintela <quintela@redhat.com>
Message-id: 1427385385-30571-1-git-send-email-eduardo.otubo@profitbricks.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>