mraa: initial implementation of "hooks"

* Should allow for more platform quirks to be handled by mraa without
* massive conditional areas per platform.

Signed-off-by: Thomas Ingleby <thomas.c.ingleby@intel.com>

include/intel_galileo_rev_d.h

@@ -24,9 +24,9 @@
 
 #pragma once
 
-#include "mraa.h"
+#include "mraa_adv_func.h"
 
 #define MRAA_INTEL_GALILEO_REV_D_PINCOUNT 25
 
 mraa_board_t*
-mraa_intel_galileo_rev_d();
+mraa_intel_galileo_rev_d(mraa_adv_func* adv);