Converted trapezoid_profile over to monotonic_clock

This also involves updating all the callers, and updating
control_loop's frequency variable.

Change-Id: Ic88d2715db30efcc25721da2dd8c89910ede7788
diff --git a/aos/common/util/trapezoid_profile.h b/aos/common/util/trapezoid_profile.h
index fe63352..cc91db1 100644
--- a/aos/common/util/trapezoid_profile.h
+++ b/aos/common/util/trapezoid_profile.h
@@ -17,7 +17,7 @@
 class TrapezoidProfile {
  public:
   // delta_time is how long between each call to Update.
-  TrapezoidProfile(const time::Time &delta_time);
+  TrapezoidProfile(::std::chrono::nanoseconds delta_time);
 
   // Updates the state.
   const Eigen::Matrix<double, 2, 1> &Update(double goal_position,
@@ -58,7 +58,7 @@
   double maximum_velocity_;
 
   // How long between calls to Update.
-  const time::Time timestep_;
+  ::std::chrono::nanoseconds timestep_;
 
   DISALLOW_COPY_AND_ASSIGN(TrapezoidProfile);
 };