Rover: use AP_ServoRelayEvents singleton

APMrover2/GCS_Mavlink.cpp

@@ -1420,11 +1420,6 @@ AP_Camera *GCS_MAVLINK_Rover::get_camera() const
 #endif
 }
 
-AP_ServoRelayEvents *GCS_MAVLINK_Rover::get_servorelayevents() const
-{
-    return &rover.ServoRelayEvents;
-}
-
 AP_AdvancedFailsafe *GCS_MAVLINK_Rover::get_advanced_failsafe() const
 {
 #if ADVANCED_FAILSAFE == ENABLED

APMrover2/GCS_Mavlink.h

@@ -20,7 +20,6 @@ protected:
     AP_Mission *get_mission() override;
     AP_Rally *get_rally() const override { return nullptr; };
     AP_Camera *get_camera() const override;
-    AP_ServoRelayEvents *get_servorelayevents() const override;
     AP_AdvancedFailsafe *get_advanced_failsafe() const override;
     AP_VisualOdom *get_visual_odom() const override;
     const AP_FWVersion &get_fwver() const override;