[core] Moved nfc_adapter_set_enabled() to internal header. JB#48413

It's still exported from nfcd in order to maintain plugin ABI but
removed from the public headers. From now on it's considered an
internal function. Its use is obviously discouraged.

Plugins should use nfc_manager_set_enabled() instead.

core/include/nfc_adapter.h

@@ -1,6 +1,6 @@
 /*
- * Copyright (C) 2018-2020 Jolla Ltd.
- * Copyright (C) 2018-2020 Slava Monich <slava.monich@jolla.com>
+ * Copyright (C) 2018-2021 Jolla Ltd.
+ * Copyright (C) 2018-2021 Slava Monich <slava.monich@jolla.com>
  *
  * You may use this file under the terms of BSD license as follows:
  *
@@ -83,11 +83,6 @@ void
 nfc_adapter_unref(
     NfcAdapter* adapter);
 
-void
-nfc_adapter_set_enabled(
-    NfcAdapter* adapter,
-    gboolean enabled);
-
 void
 nfc_adapter_request_power(
     NfcAdapter* adapter,

core/src/nfc_adapter_p.h

@@ -1,6 +1,6 @@
 /*
- * Copyright (C) 2018-2020 Jolla Ltd.
- * Copyright (C) 2018-2020 Slava Monich <slava.monich@jolla.com>
+ * Copyright (C) 2018-2021 Jolla Ltd.
+ * Copyright (C) 2018-2021 Slava Monich <slava.monich@jolla.com>
  *
  * You may use this file under the terms of BSD license as follows:
  *
@@ -37,6 +37,11 @@
 
 #include <nfc_adapter.h>
 
+void
+nfc_adapter_set_enabled(
+    NfcAdapter* adapter,
+    gboolean enabled); /* It used to be public and stays exported */
+
 void
 nfc_adapter_set_name(
     NfcAdapter* adapter,