Interrupts: remove C prototype and keep only C++ prototypes

attachInterrupt() C prototypes was not usable from C source file
(inheritace of former pure C implementation), and causes ambiguity
when used with lambda function as callback
Fixes #1601

Signed-off-by: Alexandre Bourdiol <[email protected]>

Author: ABOSTM

cores/arduino/WInterrupts.h

@@ -26,11 +26,7 @@
 
   typedef std::function<void(void)> callback_function_t;
   void attachInterrupt(uint32_t pin, callback_function_t callback, uint32_t mode);
-
+  void detachInterrupt(uint32_t pin);
 #endif
 
-void attachInterrupt(uint32_t pin, void (*callback)(void), uint32_t mode);
-
-void detachInterrupt(uint32_t pin);
-
 #endif /* _WIRING_INTERRUPTS_ */