mtpd: whitelist 'nanosleep' syscall in seccomp-bpf filter

BUG=chromium:693673
TEST=Verified that mtpd runs properly on different platforms.

Change-Id: Ifb59fa0f1aa5c0fd23c9b2b7aa4c1d2102336092
Reviewed-on: https://chromium-review.googlesource.com/444035
Commit-Ready: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
3 files changed