ArduCopter: Remove i2c lockup count

This was returned only for a single bus and on all supported platforms
this is hardcoded to 0.

ArduCopter/GCS_Mavlink.cpp

@@ -337,7 +337,7 @@ void NOINLINE Copter::send_hwstatus(mavlink_channel_t chan)
     mavlink_msg_hwstatus_send(
         chan,
         hal.analogin->board_voltage()*1000,
-        hal.i2c->lockup_count());
+        0);
 }
 
 void NOINLINE Copter::send_servo_out(mavlink_channel_t chan)

ArduCopter/Log.cpp

@@ -363,7 +363,7 @@ void Copter::Log_Write_Performance()
         num_loops        : perf_info_get_num_loops(),
         max_time         : perf_info_get_max_time(),
         pm_test          : pmTest1,
-        i2c_lockup_count : hal.i2c->lockup_count(),
+        i2c_lockup_count : 0,
         ins_error_count  : ins.error_count(),
         log_dropped      : DataFlash.num_dropped() - perf_info_get_num_dropped(),
     };