AP_HAL_ChibiOS: add missing override keywords

This was causing CubeOrange not to build

libraries/AP_HAL_ChibiOS/CANFDIface.h

@@ -176,15 +176,15 @@ class CanIface : public uavcan::ICanIface, uavcan::Noncopyable
     int computeTimings(uavcan::uint32_t target_bitrate, Timings& out_timings);
 
     virtual uavcan::int16_t send(const uavcan::CanFrame& frame, uavcan::MonotonicTime tx_deadline,
-                                 uavcan::CanIOFlags flags);
+                                 uavcan::CanIOFlags flags) override;
 
     virtual uavcan::int16_t receive(uavcan::CanFrame& out_frame, uavcan::MonotonicTime& out_ts_monotonic,
-                                    uavcan::UtcTime& out_ts_utc, uavcan::CanIOFlags& out_flags);
+                                    uavcan::UtcTime& out_ts_utc, uavcan::CanIOFlags& out_flags) override;
 
     virtual uavcan::int16_t configureFilters(const uavcan::CanFilterConfig* filter_configs,
-            uavcan::uint16_t num_configs);
+            uavcan::uint16_t num_configs) override;
 
-    virtual uavcan::uint16_t getNumFilters() const;
+    virtual uavcan::uint16_t getNumFilters() const override;
 
     void setupMessageRam(void);
 
@@ -240,7 +240,7 @@ public:
      * Total number of hardware failures and other kinds of errors (e.g. queue overruns).
      * May increase continuously if the interface is not connected to the bus.
      */
-    virtual uavcan::uint64_t getErrorCount() const;
+    virtual uavcan::uint64_t getErrorCount() const override;
 
     /**
      * Number of times the driver exercised library's requirement to abort transmission on first error.
@@ -303,7 +303,7 @@ class CanDriver : public uavcan::ICanDriver, uavcan::Noncopyable
 
     virtual uavcan::int16_t select(uavcan::CanSelectMasks& inout_masks,
                                    const uavcan::CanFrame* (& pending_tx)[uavcan::MaxCanIfaces],
-                                   uavcan::MonotonicTime blocking_deadline);
+                                   uavcan::MonotonicTime blocking_deadline) override;
 
     static void initOnce();
     static void initOnce(uavcan::uint8_t can_number, bool enable_irqs);
@@ -341,9 +341,9 @@ public:
     int init(const uavcan::uint32_t bitrate, const CanIface::OperatingMode mode);
     int init(const uavcan::uint32_t bitrate, const CanIface::OperatingMode mode, uavcan::uint8_t can_number);
 
-    virtual CanIface* getIface(uavcan::uint8_t iface_index);
+    virtual CanIface* getIface(uavcan::uint8_t iface_index) override;
 
-    virtual uavcan::uint8_t getNumIfaces() const
+    virtual uavcan::uint8_t getNumIfaces() const override
     {
         return num_ifaces_;
     }