Plane: re-enable CLI on non-APM1/APM2 boards

ArduPlane/config.h

@@ -458,12 +458,14 @@
 #endif
 
 // use this to completely disable the CLI. We now default the CLI to
-// off as it really is no longer needed except for special developer
-// testing. This also allows us to keep supporting the APM2 for a bit
-// longer, as it saves us 20k of flash
+// off on smaller boards.
 #ifndef CLI_ENABLED
+#if HAL_CPU_CLASS > HAL_CPU_CLASS_16
+ # define CLI_ENABLED ENABLED
+#else
  # define CLI_ENABLED DISABLE
 #endif
+#endif
 
 // use this to disable geo-fencing
 #ifndef GEOFENCE_ENABLED