control_allocator: remove failed motor from effectiveness

- limit to handling only 1 motor failure
- Log which motor failures are handled
- Remove motor from effectiveness matrix without
  recomputing the scale / normalization

src/modules/control_allocator/module.yaml

@@ -436,6 +436,19 @@ parameters:
             max: 1
             default: [0.05, 0.15, 0.25, 0.35, 0.45]
 
+        # Others
+        CA_FAILURE_MODE:
+            description:
+                short: Motor failure handling mode
+                long: |
+                    This is used to specify how to handle motor failures
+                    reported by failure detector.
+            type: enum
+            values:
+                0: Ignore
+                1: Remove first failed motor from effectiveness
+            default: 0
+
 # Mixer
 mixer:
     actuator_types: