Remove timer in favor of sdeventplus/utility/timer

This removes the custom timer implementation and moves to the
sdeventplus utility. Functionally this should make no change

Tested:
    Built and run through the unit test suite.

Change-Id: Ib7ee90d489d5db72496aaaca91c3cf5490ad47d6
Signed-off-by: William A. Kennington III <wak@google.com>
14 files changed