[wpilib] Prefix all NI DS specific controller classes (#8596)

Easier then the last one that put everything in a sub namespace. By
prefixing the name less things break, and intellisense will be less
confusing to new users during the transition.

wpilibcExamples/src/main/cpp/examples/DifferentialDriveBot/cpp/Robot.cpp

@@ -3,7 +3,7 @@
 // the WPILib BSD license file in the root directory of this project.
 
 #include "Drivetrain.hpp"
-#include "wpi/driverstation/XboxController.hpp"
+#include "wpi/driverstation/Gamepad.hpp"
 #include "wpi/framework/TimedRobot.hpp"
 #include "wpi/math/filter/SlewRateLimiter.hpp"
 
@@ -15,14 +15,14 @@ class Robot : public wpi::TimedRobot {
   }
 
   void TeleopPeriodic() override {
-    // Get the x speed. We are inverting this because Xbox controllers return
+    // Get the x speed. We are inverting this because gamepads return
     // negative values when we push forward.
     const auto xSpeed = -m_speedLimiter.Calculate(m_controller.GetLeftY()) *
                         Drivetrain::kMaxSpeed;
 
     // Get the rate of angular rotation. We are inverting this because we want a
     // positive value when we pull to the left (remember, CCW is positive in
-    // mathematics). Xbox controllers return positive values when you pull to
+    // mathematics). Gamepads return positive values when you pull to
     // the right by default.
     const auto rot = -m_rotLimiter.Calculate(m_controller.GetRightX()) *
                      Drivetrain::kMaxAngularSpeed;
@@ -31,7 +31,7 @@ class Robot : public wpi::TimedRobot {
   }
 
  private:
-  wpi::XboxController m_controller{0};
+  wpi::Gamepad m_controller{0};
 
   // Slew rate limiters to make joystick inputs more gentle; 1/3 sec from 0
   // to 1.