ar71xx: Onion Omega is BROKEN

This device doesn't have an Ethernet port, and even with the Ethernet
shield, eth0 is not configured.

(cherry picked from commit a44a5dce)

docs/index.rst

@@ -174,10 +174,6 @@ ar71xx-generic
 
   - Koala [#ath10k]_
 
-* Onion
-
-  - Omega
-
 * OpenMesh
 
   - A40

targets/ar71xx-generic

@@ -137,7 +137,9 @@ factory
 
 # Onion
 
-device onion-omega onion-omega
+if [ "$BROKEN" ]; then
+device onion-omega onion-omega # BROKEN: no ethernet
+fi
 
 
 # OpenMesh