Add Kalanga (kck)

Requested at
https://translatewiki.net/wiki/Thread:Support/Please_add_the_Kalanga_Language

Autonym according to Ethnologue.

data/langdb.yaml

@@ -308,6 +308,7 @@ languages:
   kbd: [Cyrl, [EU, ME], адыгэбзэ]
   kbp: [Latn, [AF], Kabɩyɛ]
   kcg: [Latn, [AF], Tyap]
+  kck: [Latn, [AF], tjikalanga]
   kea: [Latn, [AF], kabuverdianu]
   ken: [Latn, [AF], kɛ́nyáŋ]
   kg: [Latn, [AF], Kongo]

data/language-data.json

@@ -1970,6 +1970,13 @@
             ],
             "Tyap"
         ],
+        "kck": [
+            "Latn",
+            [
+                "AF"
+            ],
+            "tjikalanga"
+        ],
         "kea": [
             "Latn",
             [
@@ -6380,6 +6387,7 @@
             "sn",
             "en",
             "nd",
+            "kck",
             "ny",
             "ve",
             "tn"