gpio-mailbox: make it almost as good as Spanner.

Slightly adjust the time delay and LED sequence algorithms to take into
account wall-clock time instead of only monotonic time.  Now if you have a
bunch of brunos all blinking their lights, they're all pleasantly
synchronized.

Change-Id: Ife26b809ac2b91582ad9e93ec7b7752e01e70180
1 file changed