Rover: remove ability to use DCM as AHRS

Rover/Log.cpp

@@ -12,10 +12,9 @@ void Rover::Log_Write_Attitude()
 
     ahrs.Write_Attitude(targets);
 
-#if AP_AHRS_NAVEKF_AVAILABLE
     AP::ahrs_navekf().Log_Write();
     ahrs.Write_AHRS2();
-#endif
+
     ahrs.Write_POS();
 
     // log steering rate controller

Rover/Parameters.cpp

@@ -343,7 +343,6 @@ const AP_Param::Info Rover::var_info[] = {
     // @Path: ../libraries/AP_GPS/AP_GPS.cpp
     GOBJECT(gps, "GPS", AP_GPS),
 
-#if AP_AHRS_NAVEKF_AVAILABLE
 #if HAL_NAVEKF2_AVAILABLE
     // @Group: EK2_
     // @Path: ../libraries/AP_NavEKF2/AP_NavEKF2.cpp
@@ -354,7 +353,6 @@ const AP_Param::Info Rover::var_info[] = {
     // @Group: EK3_
     // @Path: ../libraries/AP_NavEKF3/AP_NavEKF3.cpp
     GOBJECTN(ahrs.EKF3, NavEKF3, "EK3_", NavEKF3),
-#endif
 #endif
 
     // @Group: RPM

Rover/Rover.h

@@ -162,9 +162,7 @@ private:
 
     AP_L1_Control L1_controller{ahrs, nullptr};
 
-#if AP_AHRS_NAVEKF_AVAILABLE
     OpticalFlow optflow;
-#endif
 
 #if OSD_ENABLED || OSD_PARAM_ENABLED
     AP_OSD osd;