Add comments about keeping other SPI chips disabled

https://forum.pjrc.com/threads/27409-Play-RAW-from-Serial-Flash?p=91876&viewfull=1#post91876

examples/CopyFromSD/CopyFromSD.ino

   //SPI.setSCK(14);  // Audio shield has SCK on pin 14
   //SPI.setMOSI(7);  // Audio shield has MOSI on pin 7
 
+  //uncomment these if you have other SPI chips connected
+  //to keep them disabled while using only SerialFlash
+  //pinMode(4, INPUT_PULLUP);
+  //pinMode(10, INPUT_PULLUP);
+
   // wait up to 10 seconds for Arduino Serial Monitor
   unsigned long startMillis = millis();
   while (!Serial && (millis() - startMillis < 10000)) ;

examples/EraseEverything/EraseEverything.ino

   //SPI.setSCK(14);  // Audio shield has SCK on pin 14
   //SPI.setMOSI(7);  // Audio shield has MOSI on pin 7
 
+  //uncomment these if you have other SPI chips connected
+  //to keep them disabled while using only SerialFlash
+  //pinMode(4, INPUT_PULLUP);
+  //pinMode(10, INPUT_PULLUP);
+
   // wait up to 10 seconds for Arduino Serial Monitor
   unsigned long startMillis = millis();
   while (!Serial && (millis() - startMillis < 10000)) ;

examples/ListFiles/ListFiles.ino

   //SPI.setSCK(14);  // Audio shield has SCK on pin 14
   //SPI.setMOSI(7);  // Audio shield has MOSI on pin 7
 
+  //uncomment these if you have other SPI chips connected
+  //to keep them disabled while using only SerialFlash
+  //pinMode(4, INPUT_PULLUP);
+  //pinMode(10, INPUT_PULLUP);
+
   // wait for Arduino Serial Monitor
   while (!Serial) ;
   delay(100);

examples/RawHardwareTest/RawHardwareTest.ino

   //SPI.setSCK(14);  // Audio shield has SCK on pin 14
   //SPI.setMOSI(7);  // Audio shield has MOSI on pin 7
 
+  //uncomment these if you have other SPI chips connected
+  //to keep them disabled while using only SerialFlash
+  //pinMode(4, INPUT_PULLUP);
+  //pinMode(10, INPUT_PULLUP);
+
   while (!Serial) ;
   delay(100);