Tune drivetrain.

Add force knob, efficiency, IMU

Change-Id: I4fd12665490d4e535d5890c2edf8ae611938333d
diff --git a/y2012/control_loops/drivetrain/drivetrain_base.cc b/y2012/control_loops/drivetrain/drivetrain_base.cc
index 6f817f8..1e0cfad 100644
--- a/y2012/control_loops/drivetrain/drivetrain_base.cc
+++ b/y2012/control_loops/drivetrain/drivetrain_base.cc
@@ -22,6 +22,7 @@
       ::frc971::control_loops::drivetrain::ShifterType::NO_SHIFTER,
       ::frc971::control_loops::drivetrain::LoopType::CLOSED_LOOP,
       ::frc971::control_loops::drivetrain::GyroType::SPARTAN_GYRO,
+      ::frc971::control_loops::drivetrain::IMUType::IMU_X,
 
       ::y2012::control_loops::drivetrain::MakeDrivetrainLoop,
       ::y2012::control_loops::drivetrain::MakeVelocityDrivetrainLoop,