this adds convenience definitions for MSECS_PER_SEC, USECS_PER_MSEC,
and USECS_PER_SEC along the lines of the time units in coreboot's
<timer.h>.
Change-Id: I489dc2d1ff55d137936acec74ac875dc7fbc1713
Signed-off-by: Caveh Jalali <caveh@google.com>
Reviewed-on: https://review.coreboot.org/20882
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>