[wpilib] Revert move of RomiGyro into main wpilibc/j (#3296)

This reverts commit 69e8d0b65d (#3143).

We haven't released a version with this yet, and plan to make a vendor
library instead.

wpilibcExamples/src/main/cpp/examples/RomiReference/include/subsystems/Drivetrain.h

@@ -8,10 +8,11 @@
 #include <frc/Encoder.h>
 #include <frc/Spark.h>
 #include <frc/drive/DifferentialDrive.h>
-#include <frc/romi/RomiGyro.h>
 #include <frc2/command/SubsystemBase.h>
 #include <units/length.h>
 
+#include "sensors/RomiGyro.h"
+
 class Drivetrain : public frc2::SubsystemBase {
  public:
   static constexpr double kCountsPerRevolution = 1440.0;
@@ -116,6 +117,6 @@ class Drivetrain : public frc2::SubsystemBase {
 
   frc::DifferentialDrive m_drive{m_leftMotor, m_rightMotor};
 
-  frc::RomiGyro m_gyro;
+  RomiGyro m_gyro;
   frc::BuiltInAccelerometer m_accelerometer;
 };