[luxembourg] Add Port Channel informations (related to cronos bond0 interface)

Signed-off-by: Hyacinthe Cartiaux <hyacinthe.cartiaux@uni.lu>

data/grid5000/sites/luxembourg/network_equipments/ul-grid5000-sw01.json

 {
   "channels": {
+    "1": [
+      {
+        "linecard": 1,
+        "port": 35
+      },
+      {
+        "linecard": 2,
+        "port": 44
+      }
+    ],
     "naming_pattern": "Po%CHANNELID%"
   },
   "kind": "router",

generators/input/sites/luxembourg/net-links/ul-grid5000-sw01.yaml

@@ -342,3 +342,8 @@ ul-grid5000-sw01:
           rate: 10000000000
   channels:
     naming_pattern: Po%CHANNELID%
+    "1":
+        - linecard: 1
+          port: 35
+        - linecard: 2
+          port: 44