Add Wolaytta (wal)

Requested for Wikipedia at
https://lists.wikimedia.org/hyperkitty/list/wikipedia-l@lists.wikimedia.org/thread/KODM5QNNLIKKC4THHQNJHBH3PME3YQJ7/

Autonym according to Ethnologue.

data/langdb.yaml

@@ -670,6 +670,7 @@ languages:
   vot: [Latn, [EU], Vaďďa]
   vro: [Latn, [EU], võro]
   wa: [Latn, [EU], walon]
+  wal: [Latn, [AF], Wolaytta]
   war: [Latn, [AS], Winaray]
   wls: [Latn, [PA], "Faka'uvea"]
   wo: [Latn, [AF], Wolof]

data/language-data.json

@@ -4394,6 +4394,13 @@
             ],
             "walon"
         ],
+        "wal": [
+            "Latn",
+            [
+                "AF"
+            ],
+            "Wolaytta"
+        ],
         "war": [
             "Latn",
             [
@@ -5182,6 +5189,7 @@
             "om",
             "so",
             "ti",
+            "wal",
             "aa"
         ],
         "FI": [