G9X V4 board: Conditional code for Cam's new SOMO initialisation to prevent

crash for folaks without SOMO-14 installed.

src/board_gruvin9x.cpp

@@ -103,12 +103,14 @@ inline void board_init()
 #endif
   /***************************************************/
 
+#if defined (VOICE)
   /*
    * SOMO set-up (V4 board only)
    */
   OCR4A = 0x1F4; //2ms
   TCCR4B = (1 << WGM42) | (3<<CS40); // CTC OCR1A, 16MHz / 64 (4us ticks)
   TIMSK4 |= (1<<OCIE4A); // Start the interrupt so the unit reset can occur
+#endif
 
 #if defined(EXTRA_ROTARY_ENCODERS)
   //configure uart1 here