Fix gcc printf warning

platform/mcu/x86_64/drivers/delays.c

@@ -17,6 +17,7 @@
 
 #include "delays.h"
 #include <unistd.h>
+#include <stdio.h>
 
 /**
  * Implementation of the delay functions for x86_64.

platform/mcu/x86_64/drivers/gpio.c

@@ -16,6 +16,7 @@
  ***************************************************************************/
 
 #include "gpio.h"
+#include <stdio.h>
 
 void gpio_setMode(void *port, uint8_t pin, enum Mode mode)
 {

platform/targets/linux/platform.c

@@ -17,6 +17,7 @@
 
 #include "platform.h"
 #include "gpio.h"
+#include <stdio.h>
 
 void platform_init()
 {