Rockbox Utility TTS: implement reading TTS vendor.

Support retrieving the vendor name of the TTS. This will be used by TTS string
corrections. Currently no other TTS but SAPI supports this, and only correction
strings for SAPI voices depend on the vendor information.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30609 a1c6a512-1295-4272-9138-f99709370657

rbutil/rbutilqt/base/ttscarbon.h

@@ -45,6 +45,7 @@ class TTSCarbon : public TTSBase
         bool start(QString *errStr);
         //! child class should stop
         bool stop() ;
+        QString voiceVendor(void) { return QString(); }
 
         // configuration
         //! Child class should return true, when configuration is good