Add more default values to I2S output

Author: earlephilhower

src/AudioOutputI2S.cpp

@@ -69,7 +69,10 @@ AudioOutputI2S::AudioOutputI2S(int port, bool builtInDAC)
 #endif
   i2sOn = true;
   mono = false;
+  bps = 16;
+  channels = 2;
   SetGain(1.0);
+  SetRate(44100); // Default
   this->builtInDAC = builtInDAC;
 }