Doc: mark documentation of internal functions as such to silence qdoc

Pick-to: 6.2
Change-Id: I9523511b9adf40d1280fbf320c24a79aa2860ef2
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Luca Di Sera <luca.disera@qt.io>

src/network/socket/qlocalsocket_win.cpp

@@ -81,6 +81,8 @@ qint64 QSocketPoller::getRemainingTime(const QDeadlineTimer &deadline) const
 }
 
 /*!
+    \internal
+
     Waits until new data is available for reading or write operation
     completes. Returns \c true, if we need to check pipe workers;
     otherwise it returns \c false (if an error occurred or the operation

src/network/ssl/qtlsbackend.cpp

@@ -1368,6 +1368,7 @@ namespace QTlsPrivate {
 
 /*!
     \fn QByteArray TlsKey::encrypt(Cipher cipher, const QByteArray &data, const QByteArray &passPhrase, const QByteArray &iv) const
+    \internal
 
     This function is needed to implement QSslKey::toPem() with encryption (for a private
     key). \a cipher names a block cipher to use to encrypt \a data, using