AP_Proximity: fix fallthrough in proximity switch

in the case that cygbot was selected but not compiled in we would try to insantiate a DroneCAN backend

libraries/AP_Proximity/AP_Proximity.cpp

@@ -173,8 +173,8 @@ void AP_Proximity::init()
             }
             break;
 
-        case Type::CYGBOT_D1:
 #if AP_PROXIMITY_CYGBOT_ENABLED
+        case Type::CYGBOT_D1:
         if (AP_Proximity_Cygbot_D1::detect(serial_instance)) {
             state[instance].instance = instance;
             drivers[instance] = new AP_Proximity_Cygbot_D1(*this, state[instance], params[instance], serial_instance);

libraries/AP_Proximity/AP_Proximity.h

@@ -59,7 +59,9 @@ public:
         SITL    = 10,
         AirSimSITL = 12,
 #endif
+#if AP_PROXIMITY_CYGBOT_ENABLED
         CYGBOT_D1 = 13,
+#endif
         DroneCAN = 14,
     };
 

libraries/AP_Proximity/AP_Proximity_Cygbot_D1.h

@@ -2,10 +2,6 @@
 
 #include "AP_Proximity.h"
 
-#ifndef AP_PROXIMITY_CYGBOT_ENABLED
-#define AP_PROXIMITY_CYGBOT_ENABLED HAL_PROXIMITY_ENABLED
-#endif
-
 #if (HAL_PROXIMITY_ENABLED && AP_PROXIMITY_CYGBOT_ENABLED)
 #include "AP_Proximity_Backend_Serial.h"
 

libraries/AP_Proximity/AP_Proximity_config.h

@@ -5,3 +5,7 @@
 #ifndef HAL_PROXIMITY_ENABLED
 #define HAL_PROXIMITY_ENABLED (!HAL_MINIMIZE_FEATURES && BOARD_FLASH_SIZE > 1024)
 #endif
+
+#ifndef AP_PROXIMITY_CYGBOT_ENABLED
+#define AP_PROXIMITY_CYGBOT_ENABLED HAL_PROXIMITY_ENABLED
+#endif