seccomp: fine tuning whitelist by adding times()

This was causing Qemu process to hang when using -sandbox on as
discribed on RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1004175

Signed-off-by: Eduardo Otubo <otubo@linux.vnet.ibm.com>
Tested-by: Paul Moore <pmoore@redhat.com>
Acked-by: Paul Moore <pmoore@redhat.com>