SITL: map() is a C++ function, so needs to be in C++ part of the header

this fixes the ACM build

libraries/Desktop/include/wiring.h

@@ -113,8 +113,6 @@ int analogRead(uint8_t);
 void analogReference(uint8_t mode);
 void analogWrite(uint8_t, int);
 
-long map(long , long , long , long , long );
-
 unsigned long millis(void);
 unsigned long micros(void);
 void delay(unsigned long);
@@ -133,5 +131,6 @@ void detachInterrupt(uint8_t);
 
 void setup(void);
 void loop(void);
+long map(long , long , long , long , long );
 
 #endif