EEPROM: examples: fix Serial for board Leonardo

libraries/EEPROM/examples/eeprom_crc/eeprom_crc.ino

@@ -14,6 +14,9 @@ void setup(){
   
   //Start serial
   Serial.begin(9600);
+  while (!Serial) {
+    ; // wait for serial port to connect. Needed for Leonardo only
+  }
 
   //Print length of data to run CRC on.
   Serial.print( "EEPROM length: " );

libraries/EEPROM/examples/eeprom_get/eeprom_get.ino

@@ -23,6 +23,9 @@ void setup(){
   int eeAddress = 0; //EEPROM address to start reading from
   
   Serial.begin( 9600 );
+  while (!Serial) {
+    ; // wait for serial port to connect. Needed for Leonardo only
+  }
   Serial.print( "Read float from EEPROM: " );
 
   //Get the float data from the EEPROM at position 'eeAddress'

libraries/EEPROM/examples/eeprom_put/eeprom_put.ino

@@ -25,6 +25,9 @@ struct MyObject{
 void setup(){
 
   Serial.begin(9600);
+  while (!Serial) {
+    ; // wait for serial port to connect. Needed for Leonardo only
+  }
 
   float f = 123.456f;  //Variable to store in EEPROM.
   int eeAddress = 0;   //Location we want the data to be put.